Area of Spherical Caps Wall Art Poster

A disk of positive radius \(r\) in the Euclidean plane has area \(\pi r^2\). The same formula holds for a "disk" on the surface of a sphere if the radius is measured chordally in space! If your first thought is That can't be right, you're far from alone.

Printed on high-quality yet economical poster paper with a satin finish.