Move points H and R to change the shape of the rhombus.

H = (-2.18, -1.5)
M = (1.34, 1.38)
c = Circle(H, M)
R = Point(c)
RM = Segment(R, M)
B = Mirror(H, RM)
poly1, a', c_1, a_1, b = Polygon(B, R, H, M)
HB = Segment(H, B)
O = Intersect(HB, RM)
α = Angle(B, O, R)
a = Segment(R, O)
d = Segment(B, O)
e = Segment(O, M)
f = Segment(O, H)