Question

Write a function rule for the area of a rectangle whose length is 7 ft more than its width. What is the area of the rectangle when it’s width is 8ft?

Answer 1

`A = w^2 + 7w` is the rule for the area of a rectangle.

A = 120 sq ft, when it’s width is 8 ft.

Explanation:

Here, let us assume the width of the rectangle = w

So, the length here = Width + 7 ft = (w + 7) ft

Now, AREA of a RECTANGLE = Length x Width

Substituting here the values of length and width, we get:

A = (w) x (w + 7)
`= w^2 + 7 w`

`\implies A = w^2 + 7w`

The above function is the rule for the area of a rectangle.

Given: w = 8 ft

To find the area: put w = 8 in
`A = w^2 + 7w`

We get: A = 8² + 7(8)

= 64 + 56 = 120

or, A = 120 sq ft.

Hence, area = 120 sq ft, when it’s width is 8 ft.