Question

aflati volumul unui cuboid cu diminsiunile-a)3 cm,5 cm, 8 cm.-b)9 cm ,6(3) cm, 7 cm va rogg si aria totala a unui cub cu muchia de 8 cm . 5 1/6 cm,2,1(3) cm

Answer 1

a)3 cm,5 cm, 8 cm.
V=3×5×8=120 cm³
b)9 cm ,6(3) cm, 7 cm
6,(3)=(63-6)/9=57/9
V=9×57/9×7=399 cm³

cubul are laturi egale
L=8 cm 
At=6×(8×8)=384 cm²


L=5 1/6=31/6
At=6×(31/6×31/6)=961/6 =160,1(6)cm²

L=2,1(3)=(213-21)/90=192/90=96/45=32/15
At=6×(32/15×32/15)=2048/75 =27,30(6)cm²


daca e cuboid cu cele 3 dimensiuni
At=2(8×31/6+8×32/15+31/6×32/15)=
=2(4×31/3+8×32/15+31/3×16/15)=
=2(124/3+256/15+496/45)=
=2(1860+768+496)/45=
=6248/45=138,8(4) cm²