r

a=arco AB

r_1 = 2 (slider from 0.2 to 5, step 0.1)
C = (1.7, 2.12)
c = Circle(C, r_1)
B = Point(c)
a_1 = Ray(C, B)
A = Point(c)
b = Ray(C, A)
a = CircleArc(C, B, A)
r = Segment(C, B)
e = Segment(C, A)
θ = Angle(B, C, A)
d: a / r
f = CircleSector(C, B, A)
texto2: "$\mbox{amplitude de}  \ \theta \  \mbox{em radianos} =
\displaystyle\frac{\mbox{arco} \ AB} {\mbox{raio} \ r}=\displaystyle\frac{" + (LaTeX[a]) + "} {" + (LaTeX[r]) + "}=" + (LaTeX[d]) + "\ \mbox{rad}$ "
texto1: "\mbox{amplitude de} \ \theta\ \mbox{em  graus} = " + (LaTeX[θ]) + ""