r_{1} = 6.7 (slider from 0 to 10)
M = (1.82, -3.78)
K_S_P = Circle(M, r_{1})
E = (13.32, 1.24)
P = (18.56, -5.3)
Z = (13.94, -3.62)
A = (16.18, -6.74)
B = (1.1, -7.74)
f = Ray(M, P)
M_M_P = Midpoint(M, P)
c = Circle(M_M_P, P)
T_1 = Intersect(K_S_P, c, 1)
T_2 = Intersect(K_S_P, c, 2)
g = Line(T_1, T_2)
P' = Intersect(g, f)
r = Segment(M, T_1)
i = Segment(T_1, P)

Tool: Kreisspiegelung
Input: r, M, P
Output: P'

c = Circle(M, r)
f = Segment(M, P)
A = Midpoint(f)
d = Circle(A, P)
B = Intersect(c, d, 1)
C = Intersect(c, d, 2)
g = Segment(B, C)
P' = Intersect(f, g)