How Many Triangles 2

Keywords: Starter | Problem Solving | Shape

• Liz, Somerset
• Monday, February 05, 2007
• "Provoked lots of discussion, using it with a small group the children came out to draw over shapes found on whiteboard."
• Student:Ben Clark, Year 7 St Peters Dorset
• Monday, January 21, 2008
• "It is easy; it is 28. If you count the green and yellow triangles and the halves of each square."
• Year 7, Westbourne House
• Tuesday, January 22, 2008
• "Hugo says its 44 but we all think their might be more!"
• 8B, Freebrough Specialist Engineering College
• Wednesday, January 23, 2008
• "We also think there are 44!"
• Andy, Grantham
• Wednesday, January 23, 2008
• "There are 44, unless I am very much mistaken."

 

• Mrs Myers and her Y9 brainboxes!, Woldgate College, Yorkshire
• Thursday, January 24, 2008
• "We found 44 too!"
• Mrs Warner's year 7, Burford School
• Thursday, January 31, 2008
• "We found 32 ..... "
• Nam Anh, 7T British International School
• Saturday, February 02, 2008
• "There are 44!"
• P Hillman, Year 10, BIS, Jakarta, Indonesia
• Thursday, September 04, 2008
• "Sahara found 44. George found 48! we think he has counted the same ones twice."
• 711 , Bay House School, Gosport, Hants
• Thursday, September 25, 2008
• "711 found 44 too!"
• Evan Gingrich, Mountainview class of '11
• Tuesday, October 07, 2008
• "There are 44. 8 yellow triangles. 8 green triangles. 16 halves of the four little squares. 4 halves of the whole thing. 8 quarters."
• Mrs Johnston's Yr 7 Class, Wardle High School, Rochdale, Lancs
• Friday, October 24, 2008
• "The majority of the class found 44. however some people imagined extra and found 48!!"
• Cody Robinson, Monticello High School
• Thursday, November 06, 2008
• "Its easy.. there are 44. Think of it this way.. there are 8 triangles per square. and there are six squares in the figure. That gives you 48 but you have to remember that the tilted center square has 4 triangles that are being used as part of the 8 in the smaller 4 squares. So 4 are counted twice.. 48 - 4 = 44 total triangles."
• Sakuckoinvius, Canada
• Tuesday, January 20, 2009
• "Found 44 here too.
  
  16 + (8X2) + (4X2) + (1X2) + (1X2)
  
  16= smalls ones
  (8X2) = X2 triangles
  (4X2) = X4 triangles
  (2X2) = half of the square."
• The Red Maids' School, Y7
• Thursday, January 22, 2009
• "We agree that there are 44.... But it's pretty difficult to prove!"
• P7's in Mrs Sweeney's Maths Class, Netherlee Primary School
• Thursday, January 22, 2009
• "We all really enjoyed this problem and found it fun. We worked it out logically and got the right answer! "
• Mr. Hutchinson, Harrytown High School Stockport
• Thursday, January 22, 2009
• "Abi in 10B2 from Harrytown in Stockport got 40"
• Cheltenham Bournside School, year 10
• Friday, January 23, 2009
• "We found 44 triangles after much debating.:)"
• Mr Cansdale, Hereford Technology School, Grimsby
• Friday, January 23, 2009
• "Year 11 think 44"
• 1M, St. Matthew's Academy. Scotland
• Friday, January 23, 2009
• "It was mind boggling. We thought it was 44 triangles."
• Mr Sinclair, Oban High School, Scotland
• Friday, January 23, 2009
• "Mr Sinclair's class at Oban High School, we found 44 after a class discussion. "
• Anthony, Maine
• Saturday, January 24, 2009
• "Anthony and Michael (Daddy) say 44! Hooray! We got 44. What now!"
• Oliver Driscoll, Kings Bruton
• Saturday, January 24, 2009
• "I disagree with Ben Clark. I think there are 44."
• Benjamin Bird, Belchertown MA
• Monday, February 02, 2009
• "There are 44. You have 16 small ones. you have 4 for each of the four squares which is 16 more. That's 32. Then you have 4 more big triangles. 36. 4 more bigger triangles. 40. And 4 of the biggest triangles with that makes 44. "
• Maria B., Houston, TX
• Tuesday, February 03, 2009
• "I found 48.
  They are all right triangles; therefore, if you put 4 together, you can make a square. And within that square there is the possibility of seeing 8 triangles when you make draw an X going from corner to corner.
  Count the number of squares in the puzzle (don't forget the overall square, and you'll see 6.
  6 times 8 triangles per square = 48."

 

• Greg,
• Tuesday, February 03, 2009
• "Actually you are all wrong, there are 48 triangles. No one has accounted for the 4 that head outwards from the centre line and meet in the middle of the outer lines."
• George Bush, Atlanta
• Wednesday, February 04, 2009
• "Greg and Maria, you are wrong. It is only 44. The extra triangles you are suggesting are already accounted for in the 3rd biggest triangle possible. There is only 8 of them."
• CML, New York
• Wednesday, February 04, 2009
• "44, those who counted 48 are re-counting some of them."
• Antonio, Pittsburgh
• Thursday, February 05, 2009
• "so, Maria in your method: "counting by squares", when you count the center square, if you add 8 triangles to your count you are actually counting 4 extra triangles, already counted as halves of the smallest squares. I have a better idea, COUNT BY TRIANGLES!!
  there are 4 triangle sizes
  T size: 16
  
  TT size: 16
  
  TTTT size: 8 (yes, i counted the ones pointing outwards and inwards)
  
  TTTT
  TTTT size: 4 (16+16+8+4=44)"
• ARP, Chicago, IL
• Thursday, February 05, 2009
• "The answer is forty-four. The problem with the 'square quarters and halves' method is that quarters of larger squares are in fact the halves of the smaller ones, which leads to 're-counting.' Then, staying true to that method one also has to take into consideration eighths and sixteenths, which leads to even more 're-counting' and one ends up in a big mess. In this case, counting the triangles by size is probably the best method. When one is finished counting the triangles that consist only of themselves, that number (1) is doubled, as they are all right triangles. Now one counts those that consist of two triangles, then four and finally, eight."
• Desiree Finkbeiner, Arkansas
• Thursday, February 05, 2009
• "I don't care how many people only see 44. You people are still missing 4! There are 48! there are 6 possible squares, each with 8 possible triangles. Do the math, if you divide 44 by 8 you only get 5.5
  
  Some argue that at 48 some are counted twice. I assure you, they are not counted twice. Look again."
• Chris, Melbourne, Australia
• Friday, February 06, 2009
• "There are only 44, supposed extra four that are being counted in the second largest square (the one tilted 45 degrees) are already counted within the smallest possible square (the one made up of four little triangles). People trying to use math to solve the problem via the number of squares formed are not accounting for overlap of smaller triangles counted within other squares"
• Hans, Los Angeles
• Friday, February 06, 2009
• "There are 48, and no I did not count the middle squares triangles twice. If you look opposite of the ones you think we are counting twice, you'll find 4 more triangles that we didn't count because they overlap onto two squares. From corner to corner. Plus adding on the the 4 hypotenuse triangles, that makes 8 in the large one + 8 + 8 + 8 +8 + 8."
• Ryan Whitney, Madison, WI
• Saturday, February 07, 2009
• "I personally found 48. There are 16 total small triangles (green and yellow). Next, there are 4 medium-sized triangles in each quarter of the picture (by combining a yellow and green triangle, then rotating around each quarter) for a total of 16 more. Next, there are 4 medium-sized triangles by looking at the middle of the picture and rotating around (again, each one of these is one yellow and one green triangle) for a total of 4 more. 4 large triangles are found if you consider the edges of the picture a base of a large-sized triangle. Also, 4 equally-sized large triangles are found if you take the middle axis of the picture to be triangle bases, with the tips ending at the middle of each picture edge. Lastly, you find 4 super-large triangles by halving the entire picture 4 different ways. This adds up to 48 triangles. Congrats."
• Horatio Hornblower, University at Buffalo
• Monday, February 09, 2009
• "Ryan, you are counting four of the triangles twice. The four medium sized triangles that you count by looking at the middle of the picture and rotating around you had already counted as medium sized triangles in each quarter of the picture. So the total is only 44, not 48."
• Mike, Naples, FL
• Monday, February 09, 2009
• "44, you can only count 4 triangles from the middle box."
• Eric, Houston
• Monday, February 09, 2009
• "44. For those who found 48 and are counting 20 medium(1 yellow & 1 green) trianges, it is not possible to have more medium trianges than small trianges."
• Tram Harvey, UK
• Tuesday, February 10, 2009
• "I have found 73 triangles....oh dear, am I wrong ?"
• Tram Harvey, UK
• Tuesday, February 10, 2009
• "Excuse me I have just confused with another test when you only count the triangles with the 3 points joined. That's why I gave the answer 73 ! Sorry about that ... Furthermore I have only seen your answer later when I browsed down the page."
• Allison, Pensacola
• Wednesday, February 11, 2009
• "Ok, anyone who listens to the actual answer is wrong. There are 48 triangles not 44. Its really hard to explain but I went over it too many times and there ARE 48 triangles."
• Laura , Los Angeles, CA
• Wednesday, February 11, 2009
• "I agree with 48. "
• Eric Mattair, St. Petersburg, FL
• Wednesday, February 11, 2009
• "(anonymous) from Sakuckoinvius, Canada has the right total, but there's actually 4 triangles that take up half the square each"
• Ed Coyne, San Angelo TX
• Thursday, February 12, 2009
• "I got foty-fo."
• Willie Brown II, Houston, TX
• Thursday, February 12, 2009
• "44 is the correct answer without recounting existing triangles.
  
  Each small square contains 8 triangles - 8 x 4 = 32
  
  The inner square has 4(top/bottom then left/right) 2 x 2 = 4
  
  The outer square has 8 triangles - 4 inside & 4 outside - 4 + 2 = 8
  
  Total = 44
  
  The "48 count" error comes from recounting the inner triangles on both large squares.
  
  This was fun, hope everyone else enjoyed the mental exercise as well! :)"
• Civokrud, KY
• Friday, February 13, 2009
• "Eh Dudes, if you scroll down a little you'll see the answer is 44. It's awesome how they do that so we don't have to argue..."
• Mike, P-town
• Friday, February 13, 2009
• "Since Hans used hypotenuse in his theory to make 48...
  these are all right triangles
  the hypotenuse is opposite of it's 90 degree angle
  one hypotenuse can be shared by two triangles (count "mirror" sides)
  a hypotenuse that has
  1 line = 16
  2 line short = 16
  2 line long = 8
  3 line = 0
  4 line = 4
  total of 44
  
  A change in perspective may be beneficial as a teaching aid. we all learned how to count and what shape a triangle was by age 6. Now lets teach common sense."
• Eric, Miami
• Monday, February 16, 2009
• "I counted them. Its 44, and the above comments are right concerning re-counting the same triangles in order to get 48. The correct answer is 44."
• Jim, Jimdiegnan@gmail.com
• Monday, February 16, 2009
• "Great exercise and it held my family of 35 really concentrating on gettig it right."
• Colleen, NC
• Tuesday, February 17, 2009
• "I have to agree with 48.
  Based on the number of small triangles in each triangle, there are:
  16 with 1 small triangle
  20 with 2 small triangles
  8 with 4 small triangles
  4 with 8 small triangles."
• Colleen, NC
• Tuesday, February 17, 2009
• "Oops...
  I did just notice the overlap of the ones with 2 small triangles. Sorry!"

 

• Michael, United States Air Force Academy
• Wednesday, February 18, 2009
• "There are only 44. If you don't believe me, scroll down and see they're explanation. Other people have explained it to, but just SCROLL DOWN. its 44."
• Hannah, Ventura, Ca
• Sunday, February 22, 2009
• "I agree with 44 it is mathematically impossible to have 48. The error is in the smaller triangles running from the center facing outwards. The first time I counted I got 42 but failed to count 2 of the "half-square" triangles."
• Conor Craig, Rehboth Massachusetts
• Monday, February 23, 2009
• "People with 48 are double counting 4 of the squares when they look in the middle box that sits on it point... they are counting 4 inside that which are already counted when they look at the 4 quarter sections of the large box. In other words you can count 8 triangles for every box besides the one in the middle... on that one you can only count 4 because it shares 4 with he quarters of the large triangle."
• Kelsey, Mississippi
• Monday, February 23, 2009
• "There are 46 triangles. The answer diagram doesn't count the two large tranles that nake up the square. If you don't count the large two then the answer would be 44. Please re-look if you 44 to see the large two triangles.
  Need Help? Cut the square in half from the top left corner down to the bottom right. Now do you see the last two triangles?"
• Matt S., New Hampshire
• Tuesday, February 24, 2009
• "I'm a thirteen year old. And you know what? I count 44.
  I believe there are 20 triangles that DON'T have edges that touch the center.
  There are then 24 triangles that DO have edges that touch the center."
• Ruan Legaspi, Las Vegas, NV
• Friday, February 27, 2009
• "There are 44 triangles. I wear glasses and I counted them without. Please recount."
• Miguel Maldonado, Groton High School, Groton, New York
• Wednesday, March 11, 2009
• "There are 44, Helps when a math genius like me is also into art. Visualizing takes a lot of effort for some people I understand. I counted all the little 16 squares first, which I hope everyone has gotten that far. (16 unit sized)
  Then I moved on to see that there are four squares made up of four little triangles, but no more recounting unit sized triangles, move on to look at the triangles made up of putting two little ones together. There are four more on each of these squares. Look and see that these triangles I discovered have the vertex of the edges of the smallest squares. Here is where people claim that recounting is done. Well I honestly cant find more than 16 triangles made up of two unit triangles. The square in the middle seems to have four more triangles made up of two unit triangles with vertexes on the edges and in the center, but they have already been counted when looking at the ones made up in the four smallest squares. (16 made up of two)
  Looking at the square in the middle, there are triangles made up of four. only four of them because they are made up from the vertexes touching the edge of the biggest square. This center square only has these four triangles made up of four unit triangles, BUT those aren't the only ones in this whole problem. There are four more larger triangles made up of four unit sized triangles. Take a look at the sides of the biggest square. The vertexes of these next four triangles are the edges of the biggest square and the very center of the whole thing. Count... these are made up of four unit sized triangles, and we clearly did not disregard these. So there are 8 total, not 16. (8 triangles made up of four)
  Now the hunt for triangles made up of 8... the last four. Yes four not 8, if you are recounting here that's really sad. But honestly I don't know where you recounted but lets look at the last 4. Well this is actually quite simple. Look at the biggest square. These last four triangles made up of 8 unit sized triangles have vertexes only on the corners of the big square, obviously only four of them, and if you see more, then feel free to show me please. (4 made up of 8)
  16+16+8+4=!!!! what does it equal!?!?! hmm, 48!
  ha ha jk, its 44."
• Melanie Wong Age 11, Bournemouth Sch For Girls
• Friday, March 13, 2009
• "I got 44 triangles in 1 minute!"
• Ricardo Estopier-Ayala, Strake Jesuit College Prep
• Wednesday, March 18, 2009
• "The Correct answer is 44 triangles, and I couldn't be more sure.
  Here are my reasons:
  1. Let me explain why there are not 48 triangles: There are 6 squares composed of four or more triangles, which means that these 6 squares can be divide into 8 triangles. This would be 48 if some of the triangle weren't being counted twice. The triangles composed of 2 single triangles that are located in the middle(slanted) square are being counted twice. Once in the slanted square and once when counting the triangles in the four small squares. This would alter the equation of solving the number of triangles to be: 6(# of squares)*8(# of triangles produced by each square)-4(# of squares counted twice)= 44
  2. You can also break it down like this: There are
  4 triangles composed of 8 of the single triangles
  8 triangles composed of 4 of the single triangles
  16 triangles composed of 2 of the single triangles and
  16 single triangles
  All of these triangles add up to make 44 triangles."
• Mike Saldana (student) Prodigy, Ilchs
• Sunday, April 26, 2009
• "Im not here to spam on anybody else's comments, but for each square there are 4 triangles. there are 6 squares, 6x6=48-4+4=48Triangles.
  There are 4 triangles that are recounted. thas where the -4 comes from. but you people are forgetting the triangles that are heading outwards. that are not counted in the square. ."
• Aaron, Cedar Lake, IN
• Tuesday, April 28, 2009
• "I agree the answer is 44. It's not that math couldn't solve this problem, but your math is flawed if you have 48. Sure there are 6 possible squares. Actually there are 10 possible squares, if you want to look at it that way. So does that mean there are 80 triangles? If you increase the blocks from four to nine you get 120 triangles as your answer."
• 1 St Year, Scotland
• Monday, May 11, 2009
• "44!! Mr Berry's class St luke's high Barrhead."
• Zach Eveler 17, HHS North Carolina
• Thursday, May 21, 2009
• "I counted 48. If you say I counted some twice, I think you didn't look well enough. Don't just look at the small ones, and don't just look at them one way. You have to see all the possible combination's: diagonal, up, down, left, and right. Trust me, if you have good perception you will find them."
• Michelle Heinrich, Lanier Middle School
• Monday, May 25, 2009
• "Ketchup."
• Cody Fife, Ionia Michigan
• Friday, May 29, 2009
• "I dont think I am right because I get to 40 and then I cant find 4 more like everyone is saying."
• Ken, NC
• Tuesday, June 02, 2009
• "There are 48 triangles. They are easy enough to count. After reading the comments, I noticed that another person counted the squared to help determine the number of triangles. This is what I did as well, to make sure I had it right. Using the squares to help determine the number of triangles is an excellent use of math to make a complex problem more simple. You don't have to actually count the triangles to determine the answer this way, but you can if you wish, if only to verify your answer to yourself."
• Andres Velasco Y Coll, Nothingxs@gmail.com
• Tuesday, June 02, 2009
• "There's only 44.
  4 'squares' of 4 small triangles each: 16.
  4 'squares' of 2 medium triangles (each using 2 small triangles) each in 2 separate configurations (separated from diagonal top left to bottom right, separated from diagonal top right to bottom left): 16.
  1 small square in center with 4 large triangles (each using 4 small triangles), each large triangle sharing two of its small triangles with 2 other triangles: 4.
  1 large square with 4 large triangles (each using 4 small triangles), each large triangle not sharing any of its own small triangles with any of the other triangles: 4.
  1 large square of 2 very large triangles (each using 8 small triangles) each in 2 separate configurations (separated from diagonal top left to bottom right, separated from diagonal top right to bottom left): 4.
  That's 44 triangles total."
• Brian, West Milford, NJ
• Sunday, June 07, 2009
• "There are 44. There are indeed 6 squares and each square does have 8 triangles in it, which is what leads a lot of people to confirm what their eyes are telling them and state there are 48. The problem with the math, is that if one looks at the center square (the one that is rotated 45 degrees from the large square and is made up of the eight small triangles that touch the center of the largest square) 4 of the triangles created from that square (the four triangles that are created by dividing the square into 4 equal sized sections made up of 2 triangles each) are already accounted for when one counts the number of triangles made up by the 4 smallest squares.
  Said in a different way, 4 or the triangles created when dividing 4 small sqaures into triangles, are the same as 4 of the triangles created when diving the mid-sized (or center square) into quarters."
• Campuschris, Alabama
• Wednesday, June 10, 2009
• "There are 44 total triangles. I only found 40 on my own, but if you look at the bottom of the page the answer is listed."
• J Berry, Erm, Not A School, Found The Page By Chance
• Monday, June 15, 2009
• "I got 48, would like to try and prove this one way or another..."
• Dexter Churnside, Cherryille, NC
• Sunday, July 05, 2009
• "I found 48, you ask your self how? easy theres 8 triangles inside each little square times 4 triangles makes (32), nd the big square has half as many as all the little ones put togeter which is half of 32 is (16), and 16+32=?? 48."
• Ken, Providence, RI
• Sunday, July 19, 2009
• "If you think in three dimensions and you wrap around a single axis, there are 48. Cut and paste on to a paper towel tube to check it out. Okay engineering students, how many would get if you warp this around a single point like a geodesic sphere?"
• James Sessions, Crestview, Florida
• Saturday, August 15, 2009
• "There is only 44... figured this out less than a minute. BUT after reading everyone's comment that stated they found 48 made me take a second look just to recheck... I have analyzed every single section and only found 44. ."
• Jordan Beck, Seattle, WA
• Tuesday, August 25, 2009
• "Everyone who counted got 44, most people who used math got 48. A physics teacher once taught me that math isn't perfect. This just proves her right.
  I counted 44."
• Tckc, Goatstroking@yahoo.com
• Monday, October 05, 2009
• "I'm in AP physics and AP calculus and using math and just counting I got 44 because of common sense...here is my reasoning:
  in the smallest squares there are 8 triangles. 8x4=32
  in the center square there are 4...but if u count ones you have already counted before then there will be 8. so 32+4=36
  then there are 4 enormous ones using half of the square, there are 4 of these as well. 36+4=40
  and finally from the main square side, take each one and make a triangle out of it going to the center of the triangle. thus giving you the final 4 to equal 44.
  if u get over 44 your wrong. if u get under your missing something. the center square has 16 triangles total but u can only count 4 out of those 16 or you will be recounting from the smallest square."
• Kong Hang, Minneapolis, Minnesota
• Friday, October 16, 2009
• "My first time counting I got 36, after rechecking 2nd time I got 44.
  Good puzzle, made me think a bit."
• DanMcCusker, St Pauls Academy
• Wednesday, October 21, 2009
• "Most the kids spotted 44, some said 48 although dont know where they made up an extra 4 triangles!!!!!"
• Ms Somas, London
• Monday, November 23, 2009
• "My year 7s loved this! The closest a pupil got was 42 but they really did enjoy counting together."
• Year 4, West Sussex
• Thursday, December 10, 2009
• "Year 4 found 44 triangles in the square!"
• Mr Walker's S3 Class, Stromness Academy
• Wednesday, January 27, 2010
• "We also came up with 44 although Robert and Finley insisted on 16 as they reckoned the question didn't explicitly state that you could combine them - a bit pedantic?"
• Grade 9A, AGS, Abu Dhabi, UAE
• Wednesday, March 10, 2010
• "Jelena found 44 within just 1 minute and explained her findings clearly to the class. Great fun!"
• Ms S Allen, Dundee, Scotland
• Wednesday, March 31, 2010
• "My class of year 6's loved this! Well done to Matthew, Lyly, Geno and Shiv for answering it correctly first! :) It is small activities like this which will really get your brains warmed up for the day, as I tell my class."
• Miss Wisdom And 7A3,
• Thursday, May 06, 2010
• "7A3 think 44 as well - we are the best maths class ever!!!!"
• Year 8, Welshpool High School, Powys
• Friday, January 14, 2011
• "Tristan, Jack,Leanne, Jamie, Chloe and kate got 44. Ryan got 42. Mary got 99!"
• Year 5 Mere Green School, Birmingham, UK
• Friday, January 21, 2011
• "We got 44! We're aged 9-10!"
• Year 5, Monmouthshire
• Friday, January 21, 2011
• "Many of us were very close, and one member of our class got 44!"
• Yr 6 Eagles, Stanwell Fields
• Monday, January 24, 2011
• "We found 44 too!"
• Mr Moghul And 7H1, Light Hall School, Shirley
• Monday, January 24, 2011
• "My wonderful 7H1 class thought it was.... 44.... and they are spot on!!"
• Mr D Smith And Year 8, Bodmin College
• Tuesday, January 25, 2011
• "We did this as a class starter. We found there were 4 of any triangle by symmetry and counted 44 in total."
• Mr Trollgate, Wentworth High School
• Tuesday, January 25, 2011
• "Definitely 48, just counted them up."
• Mr Murden, Hayle Community School, Cornwall
• Wednesday, January 26, 2011
• "We were amazed that there was such a discussion about the answer when it was at the bottom of the page."
• D. Mcphee, Powys
• Tuesday, February 08, 2011
• "Llandrindod Wells High School Year 8
  Ben solved it in less than a minute. Followed by Lois, Emlyn, Lucy, Jake and Owain."
• Mrs R, Streethouse
• Tuesday, March 22, 2011
• "Streethouse Y5 and Y6 enjoyed this most of us found 44! Brilliant!!!"
• Nuala, Toot Hill 7T6b
• Wednesday, June 08, 2011
• "Triangle sized
  (1= I small triangle) The amount of them
  1 16
  2 16
  4 8
  8 4
  That is a rough total of my answer
  When I say size I mean the amount of tiny yellow or green ones, that fit in the triangle."
• Mitat, Kosova
• Thursday, June 30, 2011
• "There are 44 triangles ... I'm sure 100%."
• 9X1, Wintringham Grimsby
• Wednesday, July 13, 2011
• "9X1 the creme of the crop think 42 (majority)."
• Dylan, Stanwell School
• Thursday, November 10, 2011
• "Check the bottom its 44 it tells you the answer."
• Edo, Indonesia
• Friday, November 18, 2011
• "Every square has 8 triangle (4 really visible, and + 4 using diagonal line as baseline of the triangle).
  there are 4 visible small square + 1 big square with the same pattern as the small square, so there are 5 square.
  but there is 1 big square rotated 90 degree diagonally, and in this square, we can only count 4 triangle more since the other 4 is already count on small square.
  so ...
  (5 square * 8 triangle) + 4 = 40 + 4 = 44 ..."
• Bushey Meads School, Year 10 Dons
• Thursday, January 19, 2012
• "44."
• Jemery Johnston, Albany Ny
• Friday, January 20, 2012
• "There 44 total counting all the triangles that you see."
• Andrew Wells, Gwent Wales UK
• Saturday, January 21, 2012
• "I got 44 in 5 seconds . My methodology was to look at the answers and go with the majority."
• Mr C And 9x2, Yate International Academy
• Friday, January 27, 2012
• "We thought 16 then realised there were more, had a big argument then decided that is was 44 after all."
• Year 6, Stamford Green Primary School, Epsom
• Friday, January 27, 2012
• "44- we really enjoyed this problem.:-)."
• Ajay, Visakhapatnam, India
• Friday, January 27, 2012
• "The large square can be considered as a combination of (1) 4 small squares, (2) 2 vertical rectangles or 2 horizontal rectangles with each rectangle consisting of two adjacent small squares (3) one large square.
  Effectively, we have 5 squares and 4 rectangles.
  Each square has 4 triangles basing on each side with center point of the square as the top of the triangle. Also each square has two diagonals with two triangles on either side of the diagonal.
  This makes eight squares within each square and for five squares, the number of trinagles total 40.
  Each rectangle has 2 triangles basing on each of the broader side as the base with center point of the other broader side as the top of the triangle.
  The triangles with outer sides are already counted as part of the large square. Thus the four rectangles contain 4 additional triangles.
  This makes the total to 44.
  (4x4) = X1 triangles(smalls ones)
  [ 4 in each small square]
  (4X4) = X2 triangles(2 smalls ones as one)
  [ 4 in each small square]
  (4X1) = X4 triangles(4 smalls ones as one)
  [4 in the large square]
  (4x1) = x4 triangles(on vertcally and horizontally half of large square)
  [4 in the large square]
  (4X1) = X8 triangles(diagonally half of the square)
  [4 in the large square]
  (4x4) + (4X4) + (4X1) + (4X1) + (4X1) = 44."
• Aren Jay, Canada
• Saturday, January 28, 2012
• "Anywhere from 0 to 72.
  0 it is a green and yellow square.
  72 if you count all the triangles.
  216 if you assign a base and equate from there."
• N.D., Texas
• Sunday, January 29, 2012
• "Sorry to say, the solution is WRONG! There are at least 48. Take the large outside perimeter box - run 1 diagonal line from corner to corner. That makes 2 larger triangles they never counted. Remove that line and add 1 diagonal line from the opposing corners. That's 2 more for a total of 4 additional triangles that are not included in the solution.
  Thank you!"
• N.D., Texas
• Sunday, January 29, 2012
• "My BAD!!!!!! 44
  Hate it when I make myself into an idiot in public."
• Mike, Suffolk UK
• Thursday, February 02, 2012
• "Well - I may be an odd ball and need glasses but seems to be 40 to me !!!!"
• Industrial Engineer, Texas
• Friday, February 03, 2012
• "Today was the first time I notice this place on the web. It's clear that the count is 44. Many of the answers above provide the details logically.
  There are 16 small size triangles, call it basic, then
  there are 16 double size than the basic, (Each = 2 basic), then
  there are 8 quadruple size triangles (Each = 4 basic)
  And finally, there are 4 Octuple size triangles (Each = 8 basic). In other words, the latest is equl to half of the square.
  So adding all gives a count of 44."
• Roman, All Students In Mr Hunt's Class
• Thursday, February 09, 2012
• "Roman Lucas says it is 44."

How did you use this starter? Can you suggest how teachers could present or develop this resource? Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for Maths teachers anywhere in the world.
Click here to enter your comments.

If you don't have the time to provide feedback we'd really appreciate it if you could give this page a score! We are constantly improving and adding to these starters so it would be really helpful to know which ones are most useful. Simply click on a button below:

This starter has scored a mean of 4.6 out of 5 based on 884 votes.

Previous Day | This starter is for 23 January | Next Day