A rectangular athletic field is twice as long as it is wide. If the perimeter of the athletic field is 120 yards, what are the dimensions ? what is the width ?

Question

bibby · Answer

What is the perimeter of a normal rectangle where|dw:1391889706675:dw|

e.cociuba · Answer

Use "L" for length, "W" for width, and "P" for perimeter.

e.cociuba · Answer

P = 2L + 2W (perimeter is twice the length plus twice the width) 
L = 2W (twice as long as it is wide)  
P = 120 (the perimeter of the athletic field is 120 yards) 
120 = 2L + 2W 
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Substitute 2W (from the second equation) for L: 
120 = 2(2W) + 2W  
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Simplify: 
120 = 4W + 2W 
120=6W
W = 120 / 6 = 20
The field is 20 yards wide. 
Since the length is twice the width, it's 40 yards long.