A = (-1, 5)
B = (2, 4)
C = (4, 0)
D = (-2, 2)
poly1, a, b, c, d = Polygon(A, B, C, D)
e = Segment(D, B)
f = Segment(A, C)
I = Intersect(e, f)
g = Segment(A, I)
h = Segment(I, C)
i = Segment(B, I)
j = Segment(I, D)
b1: Distance[A, I] ≟ Distance[I, C]
b2: Distance[B, I] ≟ Distance[I, D]
b3: (b1 + b2) / 2.0
α = Angle(D, A, B)
β = Angle(A, B, C)
γ = Angle(B, C, D)
δ = Angle(C, D, A)
ε = Angle(C, I, B)
b4: e ≟ f
b5: b3 + b4
k = Segment(A, I)
l = Segment(I, C)
b6: b5 + b3