α = 0.9599310885968813 rad (slider from 10*° to 90*°, step 0.08726646259971647)
A = (7, 0)
B = (0, 0)
A' = Rotate(A, α, B)
β = Angle(A, B, A')
C = Point(xAxis)
a = Ray(B, C)
b = Line(A', a)
D = Point(b)
многоугольник1, b_1, a', d, c = Polygon(B, A', D, C)
e = OrthogonalLine(A', c)