P=2l+2w
l+w equals half of the perimeter
220/2=110
the ratio of the length to the width is 7:3
7x+3x=110
10x=110
x=11
7*11=77 for the length
3*11=33 for the width
A=l*w
A=77*33
A=2541 square inches for the area
maybe you are getting the formula mixed up ?!?!