Scherwinkel

α_1 = 0 rad (slider from 0 to 3.141592653589793, step 0.017453292519943295)
P = (2, 3)
a = Line(P, xAxis)
b = OrthogonalLine(P, xAxis)
A = Intersect(b, xAxis)
Q = (3, 7)
d = OrthogonalLine(Q, xAxis)
C = Intersect(d, xAxis)
f = Line(Q, xAxis)
P'_1 = Rotate(P, -α_1, A)
α = Angle(P'_1, A, P)
c = Line(A, P'_1)
P' = Intersect(a, c)
e = Line(C, c)
Q' = Intersect(f, e)
S = (8, 3)
g = OrthogonalLine(S, xAxis)
D = Intersect(g, xAxis)
h = Line(D, c)
i = Line(S, xAxis)
S' = Intersect(h, i)
m = Segment(P, S)
q = Segment(Q, P)
r = Segment(P', S')
a_1 = Segment(Q', P')
j = Segment(Q, S)
k = Segment(Q', S')
β = Angle(S, P, Q)
γ = Angle(S', P', Q')
text2: "Winkel(SPQ) = β = " + β
text3: "Winkel(S'P'Q') = γ =" + γ