Two regular pentagons are placed side by side. What’s the proportion blue : green?
Projection bias

Two regular pentagons are placed side by side. What’s the proportion blue : green?
Two regular pentagons and two diagonals. What’s the angle α?
A regular pentagon and a square share two vertices. What’s the angle α?
Three regular pentagons and two extended sides. What fraction of the total area is red?
A circle with an inscribed regular pentagon, a square and a triangle. Prove that the point lies on the circumference of the circle.
A regular pentagon, two semicircles and two chords. What’s the length proportion a : b?
Two regular pentagons share a vertex. What’s the angle α?
Two overlapping regular pentagons share two vertices. What fraction is the overlap area?
A regular pentagon with a diagonal. What is the top angle of the isosceles triangle?
A regular pentagon with a diagonal and an extended side. What is the top angle of the isosceles triangle?