Answered

The length of a rectangle is twice its width. If the area of the rectangle is 128 m², find its perimeter.



Answer :

To solve this problem, you need to follow a series of steps. Let's break it down:

1. Identify the variables:
- Let the width of the rectangle be denoted as [tex]\( w \)[/tex] meters.

2. Express the length in terms of the width:
- According to the problem, the length [tex]\( l \)[/tex] is twice the width. Therefore, [tex]\( l = 2w \)[/tex].

3. Formulate the equation for the area:
- The area [tex]\( A \)[/tex] of a rectangle is calculated by multiplying its length and its width. According to the problem, the area is 128 square meters.
- Thus, [tex]\( A = l \times w \)[/tex].
- Substituting the given values, we get:
[tex]\[ 128 = 2w \times w \][/tex]

4. Solve for the width [tex]\( w \)[/tex]:
- Simplify the equation:
[tex]\[ 128 = 2w^2 \][/tex]
- Divide both sides of the equation by 2:
[tex]\[ 64 = w^2 \][/tex]
- Take the square root of both sides to find [tex]\( w \)[/tex]:
[tex]\[ w = \sqrt{64} \][/tex]
[tex]\[ w = 8 \][/tex]

5. Determine the length [tex]\( l \)[/tex]:
- Remember that the length [tex]\( l \)[/tex] is twice the width:
[tex]\[ l = 2w = 2 \times 8 = 16 \][/tex]

6. Calculate the perimeter:
- The perimeter [tex]\( P \)[/tex] of a rectangle is given by the formula:
[tex]\[ P = 2 \times (l + w) \][/tex]
- Substitute the values of [tex]\( l \)[/tex] and [tex]\( w \)[/tex]:
[tex]\[ P = 2 \times (16 + 8) \][/tex]
[tex]\[ P = 2 \times 24 \][/tex]
[tex]\[ P = 48 \][/tex]

Therefore, the width of the rectangle is 8 meters, the length is 16 meters, and the perimeter is 48 meters.