diamètre

Dérouler la corde

r = 6.5 (slider from 0 to 30, step 0.1)
A: (0, r)
c = Circle(A, r)
C = (0, 0)
a = 359.9 (slider from 0 to 359.9, step 0.1)
C' = Rotate(C, a°, A)
α = Angle(C, A, C')
b, f = Tangent(C', c)
d_1: 2 * π * r - 2 * π * r * a / 360
e = Circle(C', d_1)
D, E = Intersect(e, b)
g = CircleArc(A, C, C')
h = Segment(C', E)
d: 2 * r
texte1: "diamètre = " + d + ""