Demostración del seno y coseno de la suma de dos ángulos
Author: Rafael Menéndez Ramos

a = 0.3839724354387525 rad (slider from 0 to 6.283185307179586, step 0.017453292519943295)
b = 0.4363323129985824 rad (slider from 0 to 1.5707963267948966, step 0.017453292519943295)
A = Intersect(xAxis, yAxis)
c = Circle(A, 1)
B, C = Intersect(c, xAxis)
C' = Rotate(C, a, A)
α = Angle(C, A, C')
f = Segment(A, C)
m = Segment(A, C')
C'' = Rotate(C', b, A)
d = Segment(C', A)
β = Angle(C', A, C'')
R = Segment(A, C'')
e = OrthogonalLine(C'', xAxis)
D = Intersect(e, xAxis)
o = Segment(C'', D)
h = OrthogonalLine(C'', m)
E = Intersect(h, m)
senβ = Segment(C'', E)
cosβ = Segment(A, E)
j = OrthogonalLine(E, xAxis)
F = Intersect(j, xAxis)
senαcosβ = Segment(E, F)
cosαcosβ = Segment(A, F)
g = Segment(C'', D)
b_1 = OrthogonalLine(E, o)
i = OrthogonalLine(E, g)
H = Intersect(i, g)
k = Segment(E, H)
G = Intersect(b_1, o)
δ = Angle(G, C'', E)
cosαsenβ = Segment(C'', G)
senαsenβ = Segment(E, G)