A rectangle with a circle and a semicircle. What is the proportion red : blue in terms of a and b?
Categories
The rising sun
Categories
The vanishing point
A square and an equilateral triangle. An extended side and diagonal meet in a point. What is the angle α?
Categories
The flying saucer
A quarter circle with four chords. What is the proportion purple : gold?
Categories
The dance
A regular hexagon, two squares and a semicircle connecting two vertices. Is the red vertex located on the semicircle?
Categories
The hidden circle
Two intersecting circles, two line segments and five points, two of which are centres. Prove that the red points are concyclic.
Categories
Big brother
Two squares and three line segments. What’s the angle α?
Categories
Missing pieces
A rectangle is divided in six similar triangles. What is the proportion green : yellow : red : blue?
Categories
The root cause
A square and an equilateral triangle are divided in several polygons. What is the proportion yellow : blue?
Categories
Round and pointy
A circle is inscribed in both a semicircle and a right triangle. The three tangency points are shown. What is the angle α?
Categories
The emerging pattern
A square, a circle and its centre. Prove that the six red points are on one circle.