Răspuns:
2) Ab=l^2 radical din 3 supra 4
16radical 3 =l^2 radical 3 supra 4
l^2radical 3=16radical3 ×4
l^2 radical 3=64 radical 3
l^2=64
l=8cm
At=Al+2Ab=96 radical 2+2×16 radical 3 =96 radical 2 + 32 radical 3=32(3radical2+radical3)
Al=Pb×h=24×4 radical 2=96 radical 2
Pb=3×l=3×8=24
V=Ab×h=16radical3×4 radical2=64 radical 6
3) 1 primă are 3 fețe laterale => Al=3×80 =240 cm^2
V=Ab×h=16radical3 ×10=160 radical 3
Ab=l^2 radical 3 /4 =8^2radical 3 /4 =64 radical 3 /4 =16 radical 3
Al=Pb×h
240=Pb×10
Pb=240:10=24
Pb=3×l
l=24:3 =8cm
