For starters, create an equation for your width, using width is 1 more than 1/4 length to get w=1+.25l. Now, use your perimeter formula and plug in your known value of perimeter. p=2w+2l => 24=2w+2l, plug in your equation for w wherever w appears, 24=2w+2l => 24=2(1+.25l)+2l, distribute the 2 and combine like terms, 24=2(1+.25l)+2l => 24=2+2.5l. Now, solve for l, 24=2+2.5l, subtract 2 from both sides, 22=2.5l, divide both sides by 2.5, l=22/2.5=8.8 meters, meaning your length is 8.8 meters.
