Question

A right cylinder has a radius of 5 and a height of 9. What is its surface area? O A. 72 units O B. 90 units O c. 45rt units O D. 108r units

Answer 1

Step-by-step explanation

The formula to find the surface area of a cylinder is:

`\begin{gathered} SA=2\pi r^2+2\pi rh\text{ } \\ \text{ Where} \\ SA\text{ is the surface area} \\ r\text{ is the radius} \\ h\text{ is the height} \end{gathered}`

In this case, we have:

`\begin{gathered} r=5 \\ h=9 \end{gathered}`
`\begin{gathered} SA=2\pi r^2+2\pi rh \\ SA=2\pi(5^2)+2\pi(5)(9) \\ SA=2\pi(25)+90\pi \\ SA=50\pi+90\pi \\ SA=140\pi \end{gathered}`Answer

B. 140π units²