m∠POA

P'

S'

c: x^(2) + y^(2) = 1
P = Point(c)
O = Intersect(xAxis, yAxis)
A = Point(c)
f = Segment(P, O)
α = Angle(A, O, P)
g = Line(O, P)
S: (α, sin(α))
C: (cos(α), 0)
i = Segment(P, C)
Q: ((cos(α) * cos(-1)) - (sin(α) * sin(-1)), (sin(α) * cos(-1)) + (cos(α) * sin(-1)))
h = Segment(O, Q)
j = OrthogonalLine(Q, xAxis)
B = Intersect(j, xAxis)
k = Segment(Q, B)
l = OrthogonalLine(S, xAxis)
D = Intersect(l, xAxis)
m = Segment(S, D)
Z: (α, y(Q))
n = Segment(Z, D)
p: x = 4
q = OrthogonalLine(P, p)
r = OrthogonalLine(Q, p)
E = Intersect(p, q)
u = Vector(P, E)
F = Intersect(p, r)
v = Vector(Q, F)
G = Point(xAxis)
s = OrthogonalLine(G, xAxis)
t = OrthogonalLine(S, s)
a = OrthogonalLine(Z, s)
H = Intersect(s, a)
w = Vector(H, Z)
I = Intersect(s, t)
b = Vector(I, S)