r = 1.5 (slider from 0 to 5, step 0.1)
h = 3 (slider from 0 to 5, step 0.1)
β = 0 rad (slider from 0° to 360°, step 1°)
a = Surface(((u * r / h) * sin(α)), ((u * r / h) * cos(α)), h - u, α, 0, β, u, 0, h)
A: (0, 0, h)
B: ((r * sin(β)), (r * cos(β)), 0)
C: ((h * sin(β)), (h * cos(β)), r + h)
B' = Rotate(B, ((-(360° - β)) * r / sqrt(r^(2) + h^(2))), Line[A, C])
D = Rotate(B, ((-(360° - β)) * r / sqrt(r^(2) + h^(2)) / 2), Line[A, C])
c = CircumcircleSector(B, D, B')
b = Circle(zAxis, (r, 0, 0))
d, e, f = Cone((0, 0, 0), (0, 0, h), r)
E = (-13.634999999999998, -2.2650000000000023)
F = (-10.384999999999998, -2.2650000000000023)