S=πR²

S = ?

B_1 = (6.88, -0.32)
C = (5.22, -0.44)
a = 21 (slider from 0 to 100, step 0.1)
k = 1.9 (slider from 1 to 20, step 0.1)
A = (-39.78287845935825, 8.013905483510555)
c = Circle(A, a)
B = (44.55977098839804, 23.84521185234507)
d = Circle(B, a * k)
D = Point(c)
E = Point(d)
R = Segment(A, D)
kR = Segment(B, E)