Quadratic equations: Perimeter and Area fencing dimensions

[Swan]

Homework Statement

The following enclosure is built using 280 m of fencing. If the enclosure has a total area of 2800 m², what are the dimensions to the nearest tenth?

Homework Equations

x = $\frac{-b ± \sqrt{b^{2}-4ac}}{2a}$

The Attempt at a Solution

Please note that the 3/2w and 5/2w were measurements I did with a ruler. I am pretty sure that is wrong since this question is not suppose to require manual measurements.

 

[SteamKing]

Assume the enclosure is L long and W wide.

What is the amount of fencing used, in terms of W and L?
What is the area of the enclosure, in terms of W and L?