t = -5 (slider from -50 to 5, step 1)
s = -20 (slider from -50 to 5, step 1)
a: 4 * x + 3 * y = 105 + 4 * s + 3 * t
b: 24 * x + 7 * y = 525 + 24 * s + 7 * t
d: (x - s)^(2) + (y - t)^(2) = 441
c: 20 * x + 21 * y = 609 + 20 * s + 21 * t
A = Intersect(d, b, 1)
D: (s, t)
B = Intersect(d, a)
E = Intersect(d, c)
e = Segment(D, E)
f = Segment(D, B)
g = Segment(D, A)
F = (-17.25523168957854, 21.241650072866843)