The pedal curve of an astroid
|
(1)
| |||
|
(2)
|
with pedal point at the center is the quadrifolium
|
(3)
| |||
|
(4)
|
Weisstein, Eric W. "Astroid Pedal Curve." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/AstroidPedalCurve.html