Question

The width of a rectangle is one half it's length. The perimeter of the rectangle is 54 cm. What are the width and length of the rectangle?

Answer 1

Width= 1/2x length=x
to find the perimeter, it's the width+width+length+length so:
1/2x+1/2x+x+x=54
3x=54
x=18
the length is 18 cm and the width is 9 cm

Answer 2

Let length of the rectangle = x.
Let width of the rectangle = x/2 (or 1/2 of x)

Remember that Area = 2L + 2W, so . . .

2x + 2(x/2) = 54

2x + (2/2)x = 54

2x + x = 54

3x = 54  -->  x = 54/3 --> x = 18

So the length of the rectangle is 18 cm and the width is 18/2 = 9 cm.