Question

A parallelogram has an area of 14 cm 2. If the dimensions of the parallelogram are doubled, what will the new area be?

Answer 1

A=bh
new area=(2b)(2h)=4bh, 4 times the original, or 56cm^2

Answer 2

Area is measured in 'square' units, so the change in area, if the sides are changed by the same ratio, can be though of the square of the change in dimensions. If the dimensions are multiplied by 2, then the area becomes 2 squared = 2*2 = 4.
If both dimensions were trippled, then it would be 3*3 to give 9 times the area.