p = 4 (slider from -5 to 15, step 0.05)
R = 0 (slider from 0 to 15, step 0.05)
ε: x = ((-p)) / 2 + R
E: (p / 2, 0)
c = Circle(E, R)
M, M' = Intersect(c, ε)
δ: x = ((-p)) / 2
a = Segment(M, E)
b = OrthogonalLine(M, δ)
Σ = Intersect(δ, b)
d = Segment(M, Σ)
Α = Point(δ)
α = Angle(M, Σ, Α)
e = Segment(E, M')
f = OrthogonalLine(M', δ)
Β = Intersect(δ, f)
β = Angle(M', Β, Σ)
g = Segment(Β, M')
Γ = Intersect(ε, δ)
Δ = Point(ε)