Question

Find the width of the rectangular prism when the surface area is 208 centimeters

Answer 1

Use the surface area formula of a rectangular prism to find the width. (I have changed it to use the same terms given in the problem).

A

=

2

(

d

w

+

h

w

+

h

d

)

Because of the given information, it is known that:

A

=

208

h

=

8

d

=

6

The width is not know, so let it keep it's variable

w

. But substitute the other values into the equation:

A

=

2

(

d

w

+

h

w

+

h

d

)

208

=

2

[

6

w

+

8

w

+

(

8

)

(

6

)

]

208

=

2

(

14

w

+

48

)

Use the distributive property to solve the right side of the equal sign:

208

=

2

(

14

w

+

48

)

208

=

28

w

+

96

112

=

28

w

112

28

=

w

4

=

w

The width is

4

.