Question

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. *

Answer 1

(i) 59.38 m^2

(ii) 64.77 m^2

Step-by-step explanation:

(i)

The lateral area of a cylinder is ...

A = πdh

A = π(4.2 m)(4.5 m) = 18.9π m^2 ≈ 59.38 m^2 . . . tank wall area

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(ii)

If that represents 11/12 of the steel used, then the steel used is ...

(12/11)(59.38 m^2) ≈ 64.77 m^2 . . . steel used