Geometry Question for Title 1 Schools: Length & Area Question?
9) If the length of a rectangle is twice the width of it, what is the length if the area is 72?
Area of a rectangle = length x width
Area for a rectangle “a” = length “l” x width “w”
Since “l” is twice “w”, then l = 2w
a = l x w
72 = 2w x w
72 = 2w2
We have to make “w” subject of formula, so we move 2 to the other side. When you move to the other side, addition becomes subtraction, multiplication becomes division, and vice versa.
72/2 = w2 (2 multiplied w at the other side)
36 = w2
6 = w
If the width is 6, then the length must be 12.