Congruent TrianglesRecognise the criteria for the congruence of triangles and solve related problems. 
This is level 1; Determining whether two triangles are congruent and finding the reason. The diagrams are not drawn to scale. Lengths and angles are not always shown in proportion.
For each pair of triangles select the correct description of congruency.


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Pairs  The classic pairs game with simple congruent shapes.
Level 1  Determining whether two triangles are congruent and finding the reason
Level 2  Further questions on recognising congruency ordered randomly
Level 3  Use your knowledge of congruent triangles to find lengths and angles
Similar Shapes  Similarity is a related concept.
Exam Style Questions  A collection of problems in the style of GCSE or IB/Alevel exam paper questions (worked solutions are available for Transum subscribers).
More Geometry including lesson Starters, visual aids, investigations and selfmarking exercises.
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The following conditions guarantee congruence:
SSS  Given the lengths of all three sides.
SAS  Given two sides and the included angle.
ASA or AAS  Given two angles and any side.
The following is a set of conditions that does not guarantee congruence:
ASS  Given two sides and an angle that is not included between them. However congruence could be confirmed if the angle is a right angle (RHS  rightangle, hypotenuse, side) or an obtuse angle or if the side not adjacent to the angle is longer than the side that is adjacent.
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