From the purple triangle ABC and the center of its inscribed circle at D, form the three colored circles (BDC), (CDA), and (ADB), with centers F, G, H, respectively, thus forming the yellow triangle FGH. Prove that there is one circle that circumscribes both triangles.
A regular hexagon and two squares. What’s the angle α?
Two regular pentagons and a circle through four vertices and two intersection points. What is is the green overlap fraction?
Two squares sharing a vertex, a diagonal and a line segment. Prove that the two angles are congruent.
What fraction of the regular hexagon is yellow?
Two squares and an equilateral triangle. The three red line segments meet in a point. What is the yellow fraction?
Two semicircles with parallel bases. Show that HF and GE intersect on the perpendicular line to AC above A.
An equilateral triangle inside a rectangle. What’s red : yellow : blue?
A square and an equilateral triangle inside a right triangle. Prove that the three red vertices are collinear.
Three congruent squares share three vertices. What’s the angle α?