A circle touches the lines OA, OB and AB where OA and OB are perpendicular. Show that the diameter of the circle is equal to the perimeter of the triangle
Three circular medallions fit in a rectangular box. Can you find the radius of the largest one?
Circle Scaling
Age 14 to 16 Challenge Level:
You are given a circle with centre O. Describe how to construct
with a straight edge and a pair of compasses, two other circles
centre O so that the three circles have areas in the ratio
1:2:3.