r = 3 (slider from 0 to 5, step 0.1)
S = (1.52, 0.3)
k = CurveCartesian(x(S) + r * sin(t), y(S) + r * cos(t), t, 0, 6.283185307179586)
A = Point(k)
B = Point(k)
o = CircleArc(S, B, A)
d: 2 * r
s: o * d
p: o / d
text1: "arc \ length \  \ \        a =" + (LaTeX[o]) + ""
text2: "diameter \ \  d =" + (LaTeX[d]) + ""
text3: "result \ \ \:\: a:d = " + (LaTeX[p]) + ""
text4: "radius  \ \   r = " + (LaTeX[r]) + ""