Question

Baileys rectangular dog pen for his Irish settler must have an area of 300 square feet. Also the length must be 10 ft longer than the width. Find the dimension of the pen

Answer 1

Width of rectangular pen = 10 feet

Length of rectangular pen = 20 feet

Explanation:

We are given the following in the question:

Area of rectangular dog pen = 300 square feet

Let
`x\text{ feet}` be the width of the rectangular pen.

Then, length of the pen is given by:

`l= (x+10)\text{ feet}`

Area of rectangular pen = Area of rectangle

`A = l* w`

Putting values, we get

`200 = (x+10)x\\200 = x^2 + 10x\\x^2 + 10x-200 = 0\\ (x + 20)(x - 10) = 0\\x = -20, x = 10`

Since, dimensions can never be negative, we get

Width of rectangular pen = 10 feet

Length of rectangular pen = 20 feet