A = Point(yAxis)
B = (3, 4)
a = Line(A, B)
C = Point(yAxis)
D = (6, 1)
b = Line(C, D)
E = Intersect(a, b)
F = Point(xAxis)
c = Line(A, F)
d = Line(C, c)
G = Intersect(a, d)
H = Intersect(b, c)
α = Angle(C, E, A)
I = (-4, 3)
e = Line(I, A)
J = Point(c)
K = (-1, 6)
f = Line(J, K)
L = Intersect(e, f)
M = Intersect(c, f)