r=2cos(3θ)
Author: Bekki George

θ = 6.283185307179586 rad (slider from 0 to 6.283185307179586, step 0.0017)
a = CurveCartesian((2 + 4 * cos(t)) * cos(t), (2 + 4 * cos(t)) * sin(t), t, 0, 6.28)
B = Point(a)
A: ((2 + 4 * cos(θ)) * cos(θ), (2 + 4 * cos(θ)) * sin(θ))
b = Segment(A, B)