Chapter 12.9, Problem 25STP

To determine

To find : Which option is correct.

Answer to Problem 25STP

Option (D)

Explanation of Solution

Given information :

The given information is, radius = $1$ in. and height = $4$ in.

Formula Used:

Surface area of cylinder $=2\pi rh+2\pi r^2=2\pi r(r+h)$

Calculation :

Surface Area of cylinder

  $\begin{array}{l}=2\times \pi \times (1)(1+4)\\ $ =10\pi {(\text{in}\text{.})}^2$=31.4\text{in}{\text{.}}^{\text{2}}\end{array}$

If r = $2$ in. and h = $0.5$ in.

So, surface Area of cylinder

  $\begin{array}{l}=2\times \pi \times 2(2+0.5)\\ =10\pi \text{ in}{\text{.}}^{\text{2}}\\ =31.4\text{ in}{\text{.}}^{\text{2}}\end{array}$

Hence, option (D) is correct.