The thickness of the bottom is the same as that of the wall. The thickness of the wall is 20 cm, and the outer diameter is 4 m and 5 m. 1 The thickness of the bottom is the same as that of the wall. The thickness of the wall is 20 cm, and the outer diameter is 4 m and 5 m 1. How many cubic meters of water can the pool hold at most? (reserve two decimal places) 2. How many cubic meters of material is needed to build this pool? 3. What is the area of plastering cement on the inner wall and ground of the pool?

The thickness of the bottom is the same as that of the wall. The thickness of the wall is 20 cm, and the outer diameter is 4 m and 5 m. 1 The thickness of the bottom is the same as that of the wall. The thickness of the wall is 20 cm, and the outer diameter is 4 m and 5 m 1. How many cubic meters of water can the pool hold at most? (reserve two decimal places) 2. How many cubic meters of material is needed to build this pool? 3. What is the area of plastering cement on the inner wall and ground of the pool?

1. 3.14 × (2-0.2) &# 178; × (2.5-0.2) = 3.14 × 1.8 & # 178; × 2.3 = 23.39 m3 2, 3.14 × 2 & # 178; × 2.5-23.39 = 31.4-23.39 = 8.01 m3 3, 2.3 × 3.14 × 1.8 × 2 + 3.14 × 1.8 & # 178; = 3.14 × 1.8 × 6.4 = 36.17 M2