Question

The length of a rectangle is $2(x+6)$ cm, and its width is half of its length. What is its perimeter?

• A. $6(x-3)$ cm
• B. $6(x-6)$ cm
• C. $3(x+6)$ cm
• D. $(6x+36)$ cm

Answer 1

The correct option is D $(6x+36)$ cm

Let length (l) $=2(x+6)cm$
then width (b) $=\frac{1}{2}\times \text{length}$
$=\frac{1}{2}\times 2(x+6)cm=(x+6)cm$

Now, perimeter of the rectangle
$=2(l+b)$
$=2\left[2\right(x+6)+(x+6\left)\right]cm$
$=2(2x+12+x+6)$
$=2(3x+18)$
$=(6x+36)cm$
Therefore, perimeter of the rectangle is $(6x+36)cm$.