Question

A cylindrical candle has a diameter of 4 inches and a height of 7 inches. To the nearest tenth, what is the total surface area of the candle?

Answer 1

We have

diameter of the candle= d=4 inches

heigth of the candle= h= 7 inches

we have a cylinder the formula for the surface area of a cylinder is

`SA=2\pi r^2+2\pi rh`

where

h=heigth=7 inches

r is half of the diameter

r=4/2=2 inches

then we substitute the values in the formula

`\begin{gathered} SA=2\pi(2)^2+2\pi(2)(7) \\ \end{gathered}`

`SA=8\pi+28\pi=36\pi=113.09\approx113.1`

the surface area of the candle rounded to the nearest tenth is 113.1 square inches