Ziehe hier, um
die Höhe zu vaiieren

Ziehe hier, um 
die Grundseite zu
variieren

A = (-2, -12)
c = 6 (slider from 1 to 8, step 0.1)
B = Point(Circle[A, c])
b = Segment(A, B)
D = Point(b)
h = 6 (slider from 1 to 8, step 0.1)
E = Point(Circle[D, h])
d = Segment(D, E)
D' = Rotate(D, 90°, D)
C = Rotate(E, 90°, D)
Höhe = Segment(D', C)
α = Angle(B, D', C)
poly1, e', a_1, b_1 = Polygon(A, B, C)