1. To make a cylindrical tin petrol tank, first find out how much tin is needed, that is, find out the (surface area) of the petrol tank; Finding the bottom area of the fuel tank is finding its (bottom area).

2. The cylinder has a bottom radius of 3cm, a height of 5cm and a surface area of (150.72) cm? The volume is (14 1.3) cm? .

3. The base radius of the cone is 6cm, the height is15cm, and the volume is (1695.6) cm? .

4. Machining a cylindrical wood into the largest cone, the volume of the cut-off part is (66.7)% of the cone volume, and the ratio of the cone volume to the cylinder volume is (1:3).

5.0.55 cubic meters =(550) cubic decimeter =(550000) cubic centimeter.

6.850000 cubic centimeters = 850 cubic decimeters = 0.85 cubic meters.

7. If the diameter of the bottom of a cylinder is 6 cm and the height is 6 cm, then its volume is (169.56) cm? .

8. The volume of a cone with a base radius of 15cm and a height of 15cm is (3532.5cm)? .

9. Cut and splice the cylinder with a bottom radius of 5 cm into an approximate cuboid, and the surface area will increase by 100 cm2. The volume of the cylinder is (250) cubic centimeters and the height is (10) centimeters.