Question

求体积第四小题，

Answer 1

底面积s＝πr²＝π×2.5×2.5＝6.25π

圆柱体积v＝sh＝6.25π×12＝75π

追答

圆锥底面积s＝πr²＝2.5×2.5×π＝6.25π

圆锥体积v＝1/3sh＝1/3×6.25π×6＝12.5π

V圆-V锥
=sh-1/3sh
=2.5×2.5×π×12-1/3×2.5×2.5×π×6
=75π-12.5π
=62.5π

Answer 2

就一个圆柱-一个圆锥
圆柱体积=π*5*5/4*12=75π
圆锥体积=π*5*5/4*6/3=12.5π
所求体积为：75π-12.5π=62.5π

追问

结果呢

追答

62.5*3.14=196.25

Answer 3

.圆周率取3。14的情况下
圆锥体=1/3*底面积*高=1/3*3.14*2.5*2.5*6=39.25
圆柱=底面积*高=3.14*2.5*2.5*12=235.5
剩余面积=圆柱体积-圆锥体体积=235.5-39.25=196.25