Quazmere Quadrant has straight edges of length 24 metres. Inside the quadrant, an orange orchard is shaped like a semicircle, with its diameter lying along one of the quadrant's straight edges and of the same length.

What would be the maximum possible radius of the Green Glade, which is also a semicircle with its diameter along the other straight edge of the quadrant, if it touches, but does not overlap, the orange orchard?