SOLUTION: The length of a rectangle is twice it's width. If it's perimeter is 54cm, find its length. Explain!

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Question 851120: The length of a rectangle is twice it's width. If it's perimeter is 54cm, find its length. Explain!
Answer by ramkikk66(644) About Me  (Show Source):
You can put this solution on YOUR website!
The length of a rectangle is twice it's width. If it's perimeter is 54cm, find its length. Explain!

Solution:
Let the width be x cm
Then the length = 2*x cm
Perimeter = 2*(length + width) = 2%2A%28x+%2B+2%2Ax%29 = 2%2A3%2Ax = 6%2Ax+=+54

Solving, x+=+54%2F6+=+9

So width = highlight%289%29 cm and length = highlight%2818%29 cm

Check: Perimeter = 2%2A%289%2B18%29+=+54. Correct!

:)