Find
(i) the lateral or curved surface area of a closed cylindrical petrol storage tank that is 4.2 m in diameter and 4.5 m high.
(ii) how much steel was actually used, if `1/(12)` of the steel actually used was wasted in making the tank

Explanation

To solve the problem step by step, we will break it down into two parts as given in the question.

### Part (i): Finding the Lateral or Curved Surface Area of the Cylinder

1. **Identify the Given Values:**
- Diameter of the cylinder (d) = 4.2 m
- Height of the cylinder (h) = 4.5 m

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