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| Question 284591:  the perimeter of a rectangle is 84 cm. The lenght is twice the width. find the length and width.
 
 
 
 
 Answer by bam878s(77)
      (Show Source): 
You can put this solution on YOUR website! The permiter is simply the distance around the object.  For example, if you wish to fence in a yard, you would calculate the distance around the yard (the permieter) in order to find the amount of fencing material you will need. If we let a = length and b = width, then we know that the perimeter is 2a+2b = 84.  Since the length is twice the width we also know that a = 2b.  So now we simply plug this into our orignal formula.
 2a + 2b = 2(2b) + 2b = 4b + 2b = 84.
 Now, we can solve for b.
 4b + 2b = 84
 6b = 84
 b = 14
 Now we know length ("a") is twice the width ("b").  So,
 a = 2b = 2(14) = 28
 So a=28 and b=14 so this is your length and width respectively.
 Hope this helps!
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