Question

$30$ circular plates, each of radius $14$ cm and thickness $3$ cm are placed one above the another to form a cylindrical solid. Find the total surface area.

Answer 1

Given, radius $14$ cm, thickness $=3$ cm, number of plates $=30$
Therefore, height of cylinder will be $3\times 30=90$ cm
We know, total surface area of cylinder $=2\pi r(r+h)$ $c{m}^2$
Therefore, total surface area $=2\pi \left(14\right)(14+(90\left)\right)=9152$ $c{m}^2$