x(t) = 2 a t y(t) = (2 a)/(t^2 + 1)
8 a^3 = 4 a^2 y + x^2 y
r(θ) = a sqrt((sqrt(81 cot^2(θ) + 12) + 9 cot(θ))^(2/3)/(3 2^(2/3) 3^(1/3)) + 1/((sqrt(81 cot^2(θ) + 12) + 9 cot(θ))^(2/3)/(3 2^(2/3) 3^(1/3)) + (2/3)^(2/3)/(sqrt(81 cot^2(θ) + 12) + 9 cot(θ))^(2/3) + 1/3)^2 + (2/3)^(2/3)/(sqrt(81 cot^2(θ) + 12) + 9 cot(θ))^(2/3) - 2/3)
(for the curve based on a circle of radius a and center (0, a))
algebraic | cubic
A = 4 π a^2
d = 3