Categories
Beginner

The headphones

A unit square, a semicircle, a right triangle and an isosceles triangle. What is the total purple area?

Categories
Beginner

En bloc

Two similar rectangles. If the small one has area 4 what is the area of the large rectangle?

Categories
Advanced

The tympanum

A regular pentagon with a diagonal and an extended side. What is the top angle of the isosceles triangle?

Categories
Intermediate

Giro d’Italia

A square with the origin halfway one of its sides. The coordinates of two vertices are given. What is the square’s area?

Categories
Intermediate

The Eye of Horus

A semicircle containing two equilateral triangles containing a circle. What fraction is blue?

Categories
Beginner

The winged messenger

A semicircle and two quarter circles pass through the same point. What’s the angle α?

Categories
Intermediate

Hard on portside

Two squares and two diagonals. Two areas are given. What is the total area?

Categories
Advanced

Points of authority

Three squares and three shared vertices. Prove the three red vertices are collinear.

Categories
Intermediate

The swinging pyramid

A regular hexagon and two equilateral triangles share a vertex. What is the area proportion blue : yellow?

Categories
Intermediate

The doors of perception

Two line segments and three rectangles, two of which have a given area. What is the yellow area?