圆锥的体积1.(1)5 45 (2)1∶3 (3)7.5 22.5 (4)22.图左: 3.14x32x8×1/3 =3.14x9x8÷3 =75.36(立方厘米) 图右:3.14x(8÷2)2x15×1/3 =3.14x16x15÷3 =251.2(立方厘米)3. 25.12x3×1/3 =25.12(立方厘米)答:这个零件的体积是25.12立方厘米。4. 16÷2=8(厘米) 3.14x82x21×1/3 =3.14x64x21×1/3 =1406.72(立方厘米)答:这个帽子所占的空间是1406.72立方厘米。5.4÷2=2(米) 3.14x22x1.5×1/3 =3.14x4x1.5×1/3 =6.28(立方米) |