r

r

Radius

M = (-13.5, 2)
r = 2 (slider from 0 to 5)
c = Circle(M, r)
D = Point(c)
f = Line(M, D)
B_1, C = Intersect(c, f)
g = Segment(D, C)
r_2 = 1 (slider from 0 to 5)
d = Circle(M, r_2)
E, E_1 = Intersect(d, g)
h = OrthogonalLine(E, g)
B, A = Intersect(c, h)
i = Segment(B, A)
α = Angle(A, E, D)
j = Segment(B, M)
k = Segment(M, A)
a = true