f(x) = x^(2)
a = Surface(t, (s * f(t)), f(t), t, 0.5, 1, s, 0, 1)
b = Surface(t, f(t), (s * f(t)), t, 0.5, 1, s, 0, 1)
c = Surface(t, 0, (s * f(t)), t, 0.5, 1, s, 0, 1)
e = 0.4 (slider from 0 to 1)
g = Surface(e, (t * f(e)), (s * f(e)), t, 0, 1, s, 0, 1)
d = Surface(1, t, s, t, 0, 1, s, 0, 1)