f(x) = abs(cos(x))
a = 6.3 (slider from 0 to 20, step 0.1)
A = Intersect(xAxis, yAxis)
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, (-6.3, 0.9998586363834151))
E = Intersect(f, j, (6.3, 0.9998586363834151))
k = Segment(D, C)
l = Segment(E, B)