The bifoliate is the quartic curve given by the Cartesian equation

and the polar equation

for .

It has a cusp at the origin .

The area of the bifoliate is given by

(OEIS A093954).

Its perimeter is

(OEIS A118289). Taking as the parameter, the bifoliate has curvature and tangential angle given by

More things to try:

Weisstein, Eric W. "Bifoliate." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Bifoliate.html