A = (3, 0, 0)
B = (0, 3, -8.881784197001252E-16)
C = (-1, -2, 0)
poly1, c, a, b = Polygon(A, B, C)
D = (0, 0, 3)
d, faceABD, faceBCD, faceACD, arêteAD, arêteBD, arêteCD = Pyramid(poly1, D)
I = Midpoint(B, C)