prot_ortocentro_prove

A = (2.14, 3.94)
B = (5.8, 1.32)
C = (1.3, 0.78)
a = Line(A, B)
b = Line(B, C)
c = Line(A, C)
d = OrthogonalLine(A, b)
e = OrthogonalLine(B, c)
D = Intersect(d, e)
f = Line(C, D)
g: f ⊥ a