Question

If the volume of a cylinder is $448\pi c{m}^3$ and height 7 cm, its total surface area will be ______________.

• A. $352c{m}^2$
• B. $754.28c{m}^2$
• C. $724.64c{m}^2$
• D. $354c{m}^2$

Answer 1

The correct option is B $754.28c{m}^2$

Let the radius of cylinder is $r$ cm and height of this is $7$ cm.

Given, volume of cylinder

$=\pi r^{2}h$

$448\pi =\pi r^2\times 7⟹r2=64⟹r=8$ cm

∴ Required total surface area of cylinder

$=2\pi r(r+h)=2\pi \times 8(8+7)$

$=2\times \frac{22}{7}\times 8\times 15$

$=754.28$ $c{m}^2$