Question 1166186
.
<pre>

Let the width be w feet;

Then the length  is (w+10) feet


The condition says

    (w+10+10)*(w+10) = 3w(w+10).


At this point, do not make FOIL.

Do not create a quadratic equation --- there is a simpler way.

Cancel the common factor (w+10) in both sides.  You will get then


    w + 10 + 10 = 3w

    w + 20      = 3w

    3w - w = 20.

    2w     = 20,

     w     = 10.


So, the dimensions of the original rectangle are  10 ft (the width)  and  10+10 = 20 ft (the length).
</pre>

Solved.


--------------


You may also think, &nbsp;what the condition means, &nbsp;geometrically.


Thinking in this way, &nbsp;you will be able to solve the entire problem &nbsp;MENTALLY &nbsp;(in your head).