polo

asse polare

ρ

y

x

θ

x = ρ cos(θ)
y = ρ sin(θ)

ρ = √(x^2 + y^2)

cos(θ) = x / ρ = x / √(x^2+y^2)

sin(θ) / y / ρ = y / √(x^2 + y2)

r = √(4^2+6.93^2) = 8 (vista algebra)

cos(θ)= x / ρ = 6.93/8 = 0.86 ( f)

acos(0.87)=

gradi = 0.52*180/3.14 =29.81 °

verifico algebricamente
calcolo ρ
calcolo cos(θ) 
calcolo angolo in radianti acos
calcolo angolo in gradi 

in modo simile calcolo sin(θ)....

A = Intersect(xAxis, yAxis)
B = Point(xAxis)
a = Ray(A, B)
C = (6.92820323027551, 4)
b = Segment(A, C)
c = OrthogonalLine(C, a)
D = Intersect(a, c)
d = Segment(D, C)
e = Segment(A, D)
r = 8.00155609865981
g = 30.955414012738853
α = Angle(D, A, C)
cos_1(θ) = 6.93 / 8
f = 0.86625
h = 0.5155940062460905
i = 29.808917197452228