$α$

$\small \small {\frac{α}{2}}$

ζ = 1.0471975511965976 rad (slider from 0 to 60°, step 0.017453292519943295)
S = Intersect(xAxis, yAxis)
A = Point(xAxis)
k = Circle(S, A)
K = Intersect(k, xAxis, 2)
K' = Rotate(K, (-ζ), S)
n = Ray(S, K')
f = Tangent(K, k)
ε = Angle(K', S, K)
M = Intersect(n, f)
α = Angle(K, S, M)
L' = Rotate(K, (-((1 / 2 * α))), S)
ξ = Angle(L', S, K)
g = Ray(S, L')
h = Ray(S, M)
L = Intersect(f, g)
i = Line(M, g)
R = Intersect(i, xAxis)
t1, l', k_1, s = Polygon(K, S, L')
M' = Intersect(k, h, 1)
j = Segment(K, M')
l = Segment(M', L')
β = Angle(L', M', K)
γ = Angle(M', K, L')
δ = Angle(M, A, K)
m = Segment(M', A)