Categories
Intermediate

The helmet

A circle, a semicircle, a chord and an altitude. What is the length of the latter in terms of a and b?

Categories
Intermediate

The fish bowl

A circle with an inscribed triangle, a tangent and two bisected angles. What is the length proportion of the red and green line segments?

Categories
Intermediate

The intersection

Two intersecting circles. Prove that the three blue line segments are of equal length.

Categories
Intermediate

Two square pegs

Two squares and a circle. What is the proportion a : b?

Categories
Intermediate

The other half

Three semicircles with diameters a, b and x. Express x in terms of a and b.

Categories
Advanced

The ice cream cone

A circle tangent to a triangle side and to the two other extended sides. What is its diameter?

Categories
Beginner

The red flag

Three squares of which two vertices are connected. If the red triangle has area 1.5 and the green square area 1, what is the side length x?

Categories
Advanced

The sliding square

A square of variable size inscribed in a semicircle of radius r. What is the maximum distance d of the lowest square vertex to the nearest semicircle corner?

Categories
Advanced

Two moons

A rectangle with two congruent circles, a semicircle and a common tangent. What is the proportion of side lengths a : b?

Categories
Intermediate

And counting

A triangle containing an altitude and the inscribed circle. One tangency point is shown. The red line segments have equal length. What is the proportion of the triangle sides a : b : c?