Question

how to do this problem??

in a cylinder , radius =7 and surface area=210π.find the height and volume of the cylinder.

Answer 1

2πr(h+r)=210π
=>7(7+h)=105
=>49+7h=105
=>7h=105-49
=>h=56÷7=8cm
so, the height is 8 cm.

volume of the cylinder=πr²h
$= \frac{22}{7} \times 7 \times 7 \times 8$
$= 22 \times 56$
$= 1232 {m}^{3}$