Question

为一幢楼房做200节长2m,横截面长20cm、宽10cm的雨水管道,需要铁皮多少平方米?

Answer 1

20cm=0.2m

10cm=0.1m

（2×0.1+0.2×0.1）×2

=（0.2+0.02）×2

=0.22×2

=0.44m2

0.44×200=88m2