\frac{\pi}{2}

π

$ \frac{3\pi}{2} $

2π

angolo in radianti  α_r

=\frac{\alpha°}{180°}\pi ≅ 

by [R-D]

1

α = 1.1344640137963142 rad (slider from 0 to 6.283185307179586, step 5*°)
A_1 = Intersect(xAxis, yAxis)
C = (1.52, 1.52)
A = Point(xAxis)
B' = Rotate(A, α, A_1)
β = Angle(A, A_1, B')
c = Circle(A_1, A)
O = (0, -4)
E = (9, -4)
a = Line(O, E)
α_r: (α, -4)
R1 = Point(a)
R2 = Point(a)
R3 = Point(a)
R4 = Point(a)
b = Segment(B', α_r)
f = Arc(c, A, B')
B = Point(f)
d = Segment(A_1, B)
testo6: "$ " + (LaTeX[f]) + " $"
testo7: " angolo in gradi = α° = " + α + ""
h = Segment(O, α_r)