Rectangular Prism

devi · #1 $Old$ 08-27-2008, 02:11 AM

The area of the top face of a rectangular prism is 54 sq. inches.If its volume is 162 cubic inches, which of the following could be the dimensions of the rectangular prism?

(a)2in. x 3in x 18in.
(b)2in. x 9in. x 9in.
(c)3in. x 6in. x 9in.
(d)6in. x 6in. x 9in.

Prove It · #2 $Old$ 08-29-2008, 05:55 AM

Quote:

Originally Posted by devi $View Post$

The area of the top face of a rectangular prism is 54 sq. inches.If its volume is 162 cubic inches, which of the following could be the dimensions of the rectangular prism?

(a)2in. x 3in x 18in.
(b)2in. x 9in. x 9in.
(c)3in. x 6in. x 9in.
(d)6in. x 6in. x 9in.

The formula for volume of a rectangular prism is Area of the base (or in this case, top face) times the height.

So if the volume is $162in^3=54\times height$ which means $height=3in$ .

So look for the option that has 3 inches as one of its dimensions, and see if the other two multiply together to give 54 (or if the three multiply to become 162).