Teorema de Thales: Si tengo dos rectas secantes g y h que cortan a un haz de rectas paralelas
f, i, j, los segmentos que definen son proporcionales.

A = (-4.94, -0.78)
A' = (-2.42, -2.36)
f = Line(A, A')
C = (-8.42, -2.64)
g = Line(C, A')
h = Line(C, A)
D = Point(h)
E = Point(h)
i = Line(D, f)
j = Line(E, f)
D' = Intersect(g, i)
E' = Intersect(g, j)
k = Segment(A, D)
l = Segment(A', D')
m = Segment(A, E)
n = Segment(A', E')
ra: k / l
texto2: "\frac{AD}{A'D'}=\frac{" + (LaTeX[k]) + "}{" + (LaTeX[l]) + "}=\frac{AE}{A'E'}=\frac{" + (LaTeX[m]) + "}{" + (LaTeX[n]) + "}=" + (LaTeX[ra]) + ""