AC=DE=AB

A = Intersect(xAxis, yAxis)
C = Point(yAxis)
a = Segment(C, A)
D = Point(a)
c = Circle(D, 5.0)
E = Intersect(c, xAxis, 2.0)
b = Segment(D, E)
B = Point(xAxis)
d = Segment(A, B)
α = Angle(B, A, C)