The bottom of this common plastic basket is stadium-shaped.

A stadium is a two-dimensional geometric shape constructed of a rectangle with semicircles at a pair of opposite sides.[1] Alternative names include discorectangle[2] and obround.[3][4]

A capsule is produced by revolving a stadium around the line of symmetry that bisects the semicircles.

The shape is used for athletics and horse racing tracks.

## Formulas

The perimeter of a stadium is calculated by the formula ${\displaystyle P=2(\pi r+a)}$ and the area by ${\displaystyle A=\pi r^{2}+2ra=r(\pi r+2a),}$ where a is the length of the straight sides and r is the radius of the semicircles.[5]