Question

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

Answer 1

$2 \times \pi \times r \times h$

Answer 2

2πrh² is the formula.......!
I hope this is the right answer