rapporteur

α = 0 rad (slider from 0 to 25*°, step 0.017453292519943295)
D = (1, 2)
E = (7, 2)
a = Segment(D, E)
B' = Rotate(E, α, D)
β_1 = Angle(E, D, B')
b = Ray(D, B')
β = 0 rad (slider from 0 to 120*°, step 0.017453292519943295)
A' = Rotate(D, -β, E)
γ = Angle(A', E, D)
c = Ray(E, A')
F = Intersect(b, c)
poly1, c_1, a_1, b_1 = Polygon(D, E, F)
d = 4 (slider from 0 to 4, step 1)
A = (8, -0.5)
B = (16.5, -0.5)
e = true
C = (-1, 7)
f = Line(C, xAxis)
G = Point(f)