Répondre :
1) V(IFBG) = 1/3 x IF x BF x FG /2 = 125/12
V(IEAH) = V(IFBG) = 125/12
2) V(IABGH) = 5^3 /2 - V(IFBG) - V(IEAH) = 125/2 - 125/6 = 125/3
3) BG = V(5² + 5²) = V50 = 5V2
Aire(ABGH) = 25V2
V(IABGH) = 1/3 x IS x Aire(ABGH)
IS = 3 V(IABGH) / (25V2) = 5 / V2