352,940 views
37 votes
37 votes
If the length of a rectangle doubles its width. Find the length of the rectangle if the perimeter is 21cm

User Pritam Chaudhari
by
3.4k points

1 Answer

12 votes
12 votes

Answer:

7cm, assuming the question is phrased as noted below.

Explanation:

I'll interpret "If the length of a rectangle doubles its width." as "If the length of a rectangle is double its width.

Let L be the width, and L the length

L = 2W

The perimeter of a rectangle is 2L + 2W

We can use L instead of 2W, and that gives us:

21 cm = 2L + L

21 cm = 3L

L = 7 cm

User Shubhayu
by
3.2k points