A = Point(xAxis)
c = Circle(A, 1)
B = Intersect(c, xAxis, 2)
C = Point(c)
C1: (x(C), 0)
t1, c_1, a, c1 = Polygon(A, C1, C)
E = Intersect(xAxis, yAxis)
G = Point(Circle[E, c1])
α = Angle(B, A, C)
AC1 = NaN
Sulg: (α, x(C1))