Question

A right cylinder has a radius of 3 and a height of 12. What is its surface area?

O A. 9077 units2
B. 72 units2
O C. 10877 units
D. 457 units2

Answer 1

Option A,
`90\pi`
`units^(2)`, is correct.

Explanation:

The formula for the surface area of a cylinder is as follows:

A=
`2\pi rh+2\pi r^(2)`

We know that the radius, r, is 3, and the height, h, is 12.

r=3

h=12

Pi will be rounded to 3.14.

Thus, applying the known values to the formula:

A=
`2(3.14)(3)(12)+2(3.14)(3)^(2)`

A=226.08+56.52

A=282.6
`units^(2)`

In accord with the given options, we must determine which one has a product of around 282.6:

A.
`90\pi =282.7433388`

B.
`72\pi =226.1946711`

C.
`108\pi =339.2920066`

D.
`45\pi =141.3716694`

Therefore, option A,
`90\pi units^(2)`, is correct.