Question

The volume of a cylinder is $616$ cubic feet and height $4$ feet. Find its curved surface area. (Use $\pi =22/7$)

• A. $88{ft}^2$
• B. $198{ft}^2$
• C. $176{ft}^2$
• D. $79{ft}^2$

Answer 1

Answer: (C)

Volume of a cylinder $=$ $\pi r^{2}h$

$\Rightarrow 616=\frac{22}{7}\times r^2\times 4$

$\Rightarrow \frac{616\times 7}{22\times 4}=r^2$

$\Rightarrow r^2=49$

$\Rightarrow r=\sqrt{49}=7ft$

Curved surface area $=$ $2\pi rh$

$=2\times \frac{22}{7}\times 7\times 4$

$=176$ square feet