Astroid (Perimeter)

Description

An astroid is a particular mathematical curve: a hypocycloid with four cusps. The astroid is a real locus of a plane algebraic curve of genus zero. The curve has a variety of names, including tetracuspid, cubocycloid, and paracycle. It is nearly identical in form to the evolute of an ellipse. An astroid created by a circle rolling inside a circle of radius “a” will have a perimeter depended on radius “a”.