Challenge Level

In the diagram, the radius of the circle is equal to the length AB. Can you find the size of angle ACB?

Challenge Level

Weekly Problem 34 - 2008

What is the area of the region common to this triangle and square?

Challenge Level

Weekly Problem 44 - 2009

A garden has the shape of a right-angled triangle. A fence goes from the corner with the right-angle to a point on the opposite side. How long is the fence?

Challenge Level

Just from the diagram, can you work out the radius of the smaller circles?