The width of the rectangle is 14 cm, and the length is 28 cm.
Let's denote the width of the rectangle as "w" and the length as "l". The problem states that the length is twice the width, so the length (l) is equal to 2 times the width (w).
The perimeter (P) of a rectangle is given by the formula:
P = 2(l + w)
In this case, the perimeter is given as 84 cm, so we can write the equation:
84 = 2(2w + w)
Now, we can solve for w:
84 = 2(3w)
Divide both sides by 2:
42 = 3w
Now, divide by 3 to find the value of w:
w = 42/3
w = 14
So, the width of the rectangle is 14 cm. Now, we can find the length (l) by using the relationship l = 2w:
l = 2 * 14
l = 28
Therefore, the length of the rectangle is 28 cm. The width is 14 cm, and the length is 28 cm.
Complete question:
The perimeter of a rectangle is 84 cm. The length is twice the width. Find the length and width.