First, it would be best to divide each side of the rectangle (4 sides) equally first that is:
900:4= 225
So, now we know each side is 225 Yards first..
Now, since the length is 70 yards longer than the width, we know that:
Length: 225+70= 295
Respectively, we also know that the width is 70 yards shorter since the length is already 70 yards longer:
Width: 225-70=155
Checking answer: (295*2) + (155*2) = 900 Yards
As our final answer, the dimension of the rectangle is 295 yards (Length) by 155 yards (Width)
Hope this help with your studies.