Obvodový a stredový uhol - príklad2

Akú veľkosť má uhol DFE?

A = (-2.99032, -0.8427)
B = (6.00968, -0.8427)
B' = Rotate(B, 32°, A)
α = Angle(B, A, B')
f = Line(A, B')
h = AngularBisector(B', A, B)
C = Point(f)
mnohouholník1, c, a, b = Polygon(A, B, C)
g = AngularBisector(A, C, B)
S = Intersect(h, g)
i = OrthogonalLine(S, f)
D = Intersect(f, i)
j = OrthogonalLine(S, c)
E = Intersect(j, c)
k = OrthogonalLine(S, a)
F = Intersect(k, a)
d = Circle(S, D)
β = Angle(D, F, E)
l = Segment(F, D)
m = Segment(F, E)