geometry puzzles

Tag: proportion

Centre of attraction

An equilateral triangle with two perpendiculars to a point that is at the same height as the triangle centre. What is red : yellow?

Three squares and a circle. The red point is a common intersection of two square sides and the circle. What is blue : green?

Two blue squares and two red right triangles. What are the proportions of the triangle sides?

Two squares share a vertex. What’s blue : green : orange?

Two squares and two line segments. If the angle α is maximal, what is yellow : red?

A square and two congruent circles with three common tangents. What’s yellow : red?

Three squares and two perpendicular line segments. What is red : yellow : blue?

A rectangle containing a right triangle. What’s red : blue?

An equilateral triangle inside a rectangle. What’s red : yellow : blue?

Advanced

Three tangent semicircles and a circle. One tangency point is shown. Prove that red : green = yellow : blue.