A regular hexagon, a square and a rectangle. What is the area proportion rectangle : square?
A circle containing a regular pentagon and two equilateral triangles. All shown points are on the circle. What’s the angle α?
Two concentric congruent squares and two red rectangles. What fraction of the total area is red?
A cyclic quadrilateral with its diagonals and two altitudes. Prove that AB is parallel to EF.
Two squares share a vertex. Three other vertices are collinear. What is the area proportion of the blue to the red square?
A square contains a right triangle. What fraction is orange?
Three tangent circles and a common tangent. The three tangency points are shown. What is α + β?
A triangle with a cevian. What is α?
A regular dodecagon and a square share two vertices. What is the area proportion square : dodecagon?
An isosceles trapezium with its inscribed circle. If the lengths are such that b-a=c-b=d-c, what is a : b : c : d?