Question 893152

Gerry wants to fence a rectangular field whose area is 1200 sq.m. He has only 100 meters of fencing so he decided to fence only the three sides of the rectangle letting the wall be the fourth side. How wide should the rectangle be? 
<pre>
Side parallel to wall can be {{{40}}} m, while other 2 sides can be {{{30}}} m each
OR
Side parallel to wall can be {{{60}}} m, while other 2 sides can be {{{20}}} m each