2-1
Author: Cristina Ochoviet, Fabián Vitabar

c = 4 (slider from 2 to 15, step 1)
b = 7 (slider from 1 to 10, step 1)
a = 7 (slider from 1 to 10, step 1)
muestra: (a + b > c) ∧ (a + c > b) ∧ (b + c > a)
n = 5 (slider from 3 to 20, step 1)
O = Midpoint(Corner[1], Corner[3])
P: O + (c, 0)
O'_1 = Rotate(O, 180° * (1 - 2 / n), P)
d = LineBisector(O, P)
e = LineBisector(P, O'_1)
A_1 = Intersect(d, e)
u = Vector(A_1, O)
A = Translate(O, u)
B = Rotate(A, -(360 * ° / n), O)
f = Circle(A, a)
g = Circle(B, b)
C = Intersect(f, g, 1)
r = Segment(A, C)
s = Segment(C, B)
t = Segment(B, A)
ladosA = Sequence(Segment[Rotate[A, i * 360 * ° / n, O], Rotate[C, i * 360 * ° / n, O]], i, 1, n)
ladosB = Sequence(Segment[Rotate[C, i * 360 * ° / n, O], Rotate[B, i * 360 * ° / n, O]], i, 1, n)
ladosC = Sequence(Segment[Rotate[B, i * 360 * ° / n, O], Rotate[A, i * 360 * ° / n, O]], i, 1, n)
polígono1, a_1, c_1, b_1, o = Polygon(A, C, B, O)
fondo = Sequence(Polygon[Rotate[A, i * 360 * ° / n, O], Rotate[C, i * 360 * ° / n, O], Rotate[B, i * 360 * ° / n, O], Rotate[O, i * 360 * ° / n, O]], i, 1, n)
contorno = If(muestra, n * (a + b), "no tiene")
texto1: "Perímetro de la estrella: " + contorno