A = (-12, 4)
B = (0, -8)
f = Line(A, B)
C = (0, -4)
D = (10, -4)
E = (2, 6)
t1, e, c, d = Polygon(C, D, E)
C' = Mirror(C, f)
D' = Mirror(D, f)
E' = Mirror(E, f)
t1', e', c', d' = Polygon(C', D', E')
a = Distance(c, d)
périmètret1 = Perimeter(t1)
Pointt1 = PointIn(t1)
périmètret1' = Perimeter(t1')
Pointt1' = PointIn(t1')
α, β, γ = InteriorAngles(t1)
δ, ε, ζ = InteriorAngles(t1')