r = 4 (slider from 1 to 10, step 1)
A = Intersect(xAxis, yAxis)
c_1 = Circle(A, r)
n = 70 (slider from 3 to 1500, step 1)
L1 = Sequence((r * cos(k * 2 * π / n), r * sin(k * 2 * π / n)), k, 0, n - 1)
nEck = Polygon(L1)
c: nEck / r^(2)
Text1 = LaTeX(c, true, true)
Vieleck1, a, b, d, e = Polygon(A, (r, 0), (r, r), (0, r))
Vieleck2, f, a_1, g = Polygon(A, Element[L1, 1], Element[L1, 2])
Text2 = Text("Fläche des " + n + "-Ecks = " + c + "*Quadratfläche")