Drehpunkt

D = (-3, 4)
B = (-2, 1)
a = Segment(B, D)
b = LineBisector(a)
A = Point(b)
C = Mirror(A, a)
poly1, c, b_1, d, a_1 = Polygon(A, B, C, D)
E = Intersect(a, b)
F = (-3.8061250927130916, 2.692057343124496)
G = (-1.3709565680182854, 3.513110332293626)
e = Line(F, G)
H = Point(e)
I = Point(e)
J = Point(e)
K = (-2.891770627502015, 1.9363153871847287)
L = (-1.8561242434364076, 2.2908609961441257)
f = Line(K, L)
g = CircleArc(E, K, L)
α = 0 rad (slider from 0 to 6.283185307179586, step 0.017453292519943295)
A' = Rotate(A, α, E)
B' = Rotate(B, α, E)
C' = Rotate(C, α, E)
D' = Rotate(D, α, E)
poly1', a', b', c', d' = Polygon(A', B', C', D')
M = Rotate(I, α, E)
N = Rotate(H, α, E)
E' = Rotate(E, α, E)
K' = Rotate(K, α, E)
L' = Rotate(L, α, E)
h = Arc(Rotate[Circle[E, K], α, E], K', L')
i = Segment(A, C)
O = Intersect(a, i)
j = false