a = CurveCartesian((sin(π / 4 + α) + sin(π / 4)) / (sin(π / 4 - α) + sin(π / 4)) * cos(α), (sin(π / 4 + α) + sin(π / 4)) / (sin(π / 4 - α) + sin(π / 4)) * sin(α), α, 0, 6.283185307179586)