F = (0, 7)
B = (0, 2)
m = Segment(F, B)
C = (5, 2)
b = Segment(B, C)
D = (5, 7)
c = Segment(C, D)
d = Segment(D, F)
K = (3.2159722222222182, 4.720138888888886)
e = 2.8000000000000003
a = 2 (slider from -1 to 4, step 0.1)