a = 2.3 (slider from 0 to 20, step 0.1)
f(x) = tan(abs(x))
A = Intersect(f, xAxis, (0, 0))
B = Point(Circle[A, a])
g = Segment(A, B)
C = Point(Circle[A, a])
h = Segment(A, C)
i = OrthogonalLine(C, xAxis)
j = OrthogonalLine(B, xAxis)
D = Intersect(f, i, (-2.3, -1.1192136417341325))
E = Intersect(f, j, (2.3, -1.1192136417341325))
k = Segment(D, C)
l = Segment(E, B)