Question

the length of a rectangle is 3cm more than the width. find the length and the width if the perimeter of the rectangle is 98cm.

Answer 1

The perimeter of a rectangle is length + length + width + width.

We know that the length of a rectangle is 3cm more than its width, which gives us the equation:  (l for length and w for width)

l = 3 + w

We also know that the perimeter of the rectangle is 98cm, which gives us the equation:

98 = 2l + 2w         (equation for perimeter of a rectangle as noted above)

We can divide both sides of this equation by 2 to get:

49 = l + w

Now we'll stick l = 3 + w into the above equation, which gives us:

49 = 3 + w + w

which simplifies to 49 = 3 + 2w.

Now we'll subtract 3 from both sides:

49 - 3 = 46

3 + 2w - 3 = 2w

which gives us 46 = 2w.

Dividing both sides by 2 gives us 23 = w.

Substituting w = 23 into the equation l = 3 + w gives us:

l = 3 + 23

l = 26cm.

Let's check our answer.  26cm is 3cm more than 23cm.  26cm + 26cm + 23cm + 23cm gives us 98cm.  The length is 26cm and the width is 23cm.