Question 237390
The Perimeter of a triangle is the sum of its 4 sides.  You can express it as: {{{P=L+L+W+W}}} ...or... {{{P=2L+2W}}}
The problems tells us the width is 2ft more than half the lenght, therefore:
{{{W=1/2L+2}}}
Now you can use the perimeter equation, but instead of using L and W, we will use L and the equivalency of W.  This will help us figure out the value of L.
Since P=40 (given)
{{{40=2L+2(1/2L+2)}}}
When you multiply 2 by 1/2L, the fraction dissapears, but remember to also multiply it by the next digit, which happens to also be 2.  Thus...
{{{40=2L+L+4}}}
{{{40-4=3L}}}
{{{L=36/3}}}
{{{L=12}}}
Now figure out W:
Since {{{W=1/2L+2)}}}
{{{W=(1/2)(12)+2}}}
{{{W=6+2}}}
{{{W=8}}}