正弦_下4桁

A = (7, -4)
B_{1} = (10, -4)
f = Ray(A, B_{1})
θ = 1.3089969389957472 (slider from 0 to pi / 2, step pi / 180)
B' = Rotate(B_{1}, θ, A)
α = Angle(B_{1}, A, B')
g = Ray(A, B')
c = Circle(A, 1)
B = Intersect(c, g)
h = OrthogonalLine(B, f)
C = Intersect(h, f)
i = Segment(B, C)
j = Segment(A, B)
k = Segment(A, C)
β = Angle(B, C, A)