The area of a rectangle can be calculated with this formula:

Where "l" is the length of the rectangle and "w" is the width.
Let's make the conversion from 9 inches to feet. Knowing that:

You get:

So you can set up that the length 17 feet 9 inches is:

And the width 11 feet 9 inches is:

Therefore, substituting values, you get that the area of the rectangle is:

The area of the rectangle rounded to the nearest square foot, is:
