An illustration showing a quadrilateral inscribed in a circle that is tangent to a line.

An illustration showing a triangle with sides b, c, and d inscribed in a circle with radius r.

An illustration showing a triangle with angles A, C, and D inscribed in a circle which is tangent to…

Illustration of an oblique view of a hollow cylinder. The portion removed from the center of the cylinder…

Illustration used to prove that triangle EFD is equilateral given that triangle ABC is equilateral and…

An illustration showing a circle with radius r inscribed in a triangle with sides a, b, and c.

An illustration showing a circle with sectors D and E inscribed in a triangle with angles, A, B, and…