.....L

R2 = 31.05 (slider from R0 to R0 + 5, step 0.01)
R1 = 20 (slider from 0 to R0, step 0.1)
Lmeplat: (2 * sqrt(R2^(2) - R1^(2)))
deplacement = 0 (slider from 0 to Lmeplat, step 0.1)
R0 = 30
O: (deplacement, R1)
M1: (deplacement + Lmeplat / 2, 0)
M2: (deplacement - Lmeplat / 2, 0)
f = Segment(M2, M1)
cercle0 = Circle(O, R0)
d = CircleArc(O, M1, M2)
Perimetre0 = Circumference(cercle0)
Perimetre2: d + f
cercle1 = Circle(O, R1)
Perimetre1 = Circumference(cercle1)
B: (Lmeplat / 2, 0)
A = Rotate(M2, (-(deplacement / R2)), O)
C = Rotate(M1, (Lmeplat - deplacement) / R2, O)
a = Segment(O, A)
b = Segment(O, B)
c = Segment(O, C)
α = Angle(A, O, B)
β = Angle(B, O, C)
e = CircleArc(O, A, M2)
g = CircleArc(O, M1, C)
B1 = NaN
roulementAB: e + Distance[M2, B]
roulementBC: g + Distance[B, M1]
de: (d * e)
Q: (deplacement, R1 - R0)
gamma_1: (Lmeplat / 2 - Distance[B, M1]) / R0
B' = Rotate(Q, (Lmeplat / 2 - Distance[B, M1]) / R0, O)
γ = Angle(Q, O, B')
h = Segment(B', B)