Chapter 6.4, Problem 13MCQ

To determine

To calculate: Dimensions of the rectangle.

Answer to Problem 13MCQ

Length $16.5$ cm, width $5.5$ cm

Explanation of Solution

Given information: The length of a rectangle is $3$ times the width. The perimeter is $44$ cm.

Calculation:

Let’s say $x$ is the width of the rectangle and $y$ is the length of a rectangle.

Now, the length of a rectangle is $3$ times the width,

  $\therefore y=3x$......(i)

Now, the perimeter is $44$ cm,

  $2x+2y=44$.....(ii)

Now, let’s substitute $y$ from the equation (i) to equation (ii),

Here, method of substitution is used because, in equation (i), $y$ does not have any cofactor.

  $2x+6x=44$

  $\therefore x=5.5$

Now, let’s put the value of $x$ in the equation (i)

  $\therefore y=3x=16.5$