The enlarged area is 4 times the original area, which is the square of the scale factor, The enlarged perimeter is 2 times the original perimeter, which is the scale factor, The perimeter is proportional to the scale factor and the area is proportional to the square of the scale factor.
When you see this kind of question use « BODMAS » 1.Add the 2 digits which is 3+7=10 2.Add the digits inside which is 0.7+1.3=2 3.Add the inside and outside 3+7(0.7+1.3) 10(2)=20
