Answer
$x=1000ft(long)$
$x=800ft(middle)$
$x=600ft(short)$
Work Step by Step
Set up an equation for appropriate conditions.
$3(x-200)=2400$
Factor out expression and add 600.
$3x-600=2400$
Divide each side by 600 and solve for x.
$3x=3000$
Solving for x give you x=1000 for the longest side. Simply subtract 200 from 1000 to get the value for the middle side. For the shortest side, simply add 200 to the length of the longest side and divide in half. Don't forget to double-check your answers!
$x=1000ft(long)$, $x=800ft(middle)$, $x=600ft(short)$