Two congruent circles and a right triangle inside a semicircle. What fraction is blue?
A circle inside a quarter circle. The triangle connects the two tangency points and the top of the quarter circle. What’s the angle α?
A square inscribed in a triangle. Two areas are given. What is the square’s area?
Two squares share a vertex. Prove that the red triangle is congruent to the blue one.
A rectangle and a square. What is the proportion purple : blue?
A rectangle with two crossing line segments. What’s the minimal shaded fraction?
Four quarter circles of radius 1, each containing a square. What is the blue area?
A triangle is split in two. What is the area of the green quadrilateral in terms of lengths a and b?
A regular pentagon with a diagonal. What is the top angle of the isosceles triangle?
A right triangle is split in two. What is the maximum yellow fraction?