A large triangle with one side tangent to a circle. The tangency point is the vertex of a blue parallelogram. What is the red area?
A rectangle containing a circle and a line segment connecting the top side to the bottom tangency point. What is its area in terms of lengths a and b?
A semicircle and an inscribed circle. Prove that the circle centre is on the parabola.
Two squares and a rectangle. Prove that the red triangles are similar.
Three squares and a line segment of which a vertex is the midpoint. What is the proportion purple : green?
Two squares and a slanted rectangle share three vertices. What is the total area?
A semicircle with two inscribed circles tangent to an altitude. What’s the angle α?
A circle, a semicircle, a chord and an altitude. What is the length of the latter in terms of a and b?
Three squares and a circle. The areas of the squares are given. What is the area of the circle?
Two congruent circles and a triangle. Prove that the triangle is isosceles.