A = (7.832031250000001, 0.48000000000000104)
B = (20.021289062500003, 1.7200000000000009)
C = (18.733691406250003, -4.499999999999998)
a = Segment(A, B)
b = Segment(B, C)
c = Segment(C, A)
I = Midpoint(a)
J = Midpoint(c)
C' = Mirror(C, I)
B' = Mirror(B, J)
d = Segment(C', A)
e = Segment(A, B')
α = Angle(A, B, C)
β = Angle(B, A, C')
γ = Angle(B, C, A)
δ = Angle(B', A, C)
ε = Angle(C, A, B)
s: Angle[A, B, C] + Angle[B, C, A] + Angle[C, A, B]
text1: "La somme des mesures des trois angles du triangle ABC est égale à " + s