# ISEE Upper Level Quantitative : How to find the surface area of a prism

## Example Questions

### Example Question #1 : How To Find The Surface Area Of A Prism

is a positive number. Which is the greater quantity?

(A) The surface area of a rectangular prism with length , width , and height

(B) The surface area of a rectangular prism with length , width , and height .

(A) is greater

(B) is greater

It is impossible to determine which is greater from the information given

(A) and (B) are equal

(A) is greater

Explanation:

The surface area of a rectangular prism can be determined using the formula:

Using substitutions, the surface areas of the prisms can be found as follows:

The prism in (A):

Regardless of the value of ,  - that is, the first prism has the greater surface area. (A) is greater.