Tool: Cercle inscrit (command Cercleinscrit)
Input: A, B, C
Output: g

poly1, c, a, b = Polygon(A, B, C)
d = AngularBisector(B, C, A)
e = AngularBisector(C, A, B)
D = Intersect(d, e)
f = OrthogonalLine(D, c)
E = Intersect(f, c)
g = Circle(D, E)

Tool: Centre du cercle inscrit (command Centreducercleinscrit)
Input: A, B, C
Output: D

d = AngularBisector(B, C, A)
e = AngularBisector(C, A, B)
D = Intersect(d, e)