Trapez drehen

A = (2, 3)
B = (8, 3)
a_2 = Line(A, B)
C = (7, 7)
b_2 = Line(C, a_2)
D = Point(b_2)
Vieleck1, a, b, c, d = Polygon(A, B, C, D)
α = 0 rad (slider from 0 to 3.141592653589793, step 0.017453292519943295)
E = Midpoint(C, B)
A' = Rotate(A, α, E)
B' = Rotate(B, α, E)
C' = Rotate(C, α, E)
D' = Rotate(D, α, E)
Vieleck1', a', b', c', d' = Polygon(A', B', C', D')
e = OrthogonalLine(D, a_2)
F = Intersect(a, e)
h = Segment(D, F)
β = Angle(B, F, D)