Equation of Cissoid of Diocles/Polar Form

Theorem
The cissoid of Diocles can be defined by the polar equation:
 * $r = 2 a \sin \theta \tan \theta$

Proof

 * CissoidOfDiocles.png

By construction:

Also see

 * Equation of Cissoid of Diocles/Cartesian Form
 * Equation of Cissoid of Diocles/Parametric Form