x

h(x) = -(0.5) * x + 8.0
g(x) = 0.25 * x + 1.0
a = 3 (slider from -5 to 10, step 0.1)
A_n: (a, 0.25 * a + 1.0)
B_n: (a + 2.0, -(0.5) * (a + 2.0) + 8.0)
Vieleck1, b, a_n, b_n, C_n = Polygon(A_n, B_n, 3.0)
α = Angle(C_n, B_n, A_n)
β = Angle(B_n, A_n, C_n)
γ = Angle(A_n, C_n, B_n)