3. 2740mm=2.74m 1525mm=1.525m 25mm=0.025m
2.74×1.525+(0.025×1.525+2.74×0.025)×2=4.39175
4. 4.25×2×8=72
3. 2740mm=2.74m 1525mm=1.525m 25mm=0.025m
2.74*1.25+0.25*2.74*2+0.025*1.525*2=4.39175(m2)
4. 4.25*2*8=72(m3)
3.2740mm=2.74m 1525mm=1.525m 25mm=0.025m
2.74×1.525+(0.025×1.525+2.74×0.025)×2=4.39175
4.8×4.5×2=72(立方米)