Susie mows a rectangular yard with a area of 72 square meters. the yard is 6 meters wide. what is the perimeter of the yard susie mows

You already know that the width of the yard is 6 and the area is 72. The area is the length times the width. So the length*6=72.
Divide by 6 on each side and you get the length to be 12 yards. 
Now to find the perimeter you find the sum of two times the width and two times the length. 
2(6)+2(12)=perimeter
12+24+36
So the perimeter is 36 yards. Hope this helps.