A = (-3.5, 1)
B = (-3.5, -2)
C = (-1.5, -2)
A'_1 = (-1, 2)
Vieleck1, c, a_1, b = Polygon(A, B, C)
d = LineBisector(A, A'_1)
A' = Mirror(A, d)
B' = Mirror(B, d)
C' = Mirror(C, d)
Vieleck1', c', a', b' = Polygon(A', B', C')
e = Circle(A, 2.0)
f = Circle(A', 2.0)
H1, H2 = Intersect(e, f)
a = Line(H1, H2)