The answer is: "10 cm" .
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Method 1)
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2L + 2w = 40 ; Since the formula for perimeter of a rectangle (Note: a square is a rectangle) is:
P = 2L + 2w ; Note: L = length; w = width; P = perimeter;
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Factor out a "2":
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" 2L + 2w = 40" ;
2 (L+ w) = 40;
Divide each side of the question by "2" ;
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[2 (L + w)] / 2 = 40 / 2 ;
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to get: (L + w) = 20 ;
Note: this "rectangle is a square" ; so L= w".
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20 /2 = 10 ;
L + w = 10 + 10 = 20.
This is a square, so each side of the square is the same length.
Each side is: 10 cm .
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Method 2)
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We are given: The perimeter (sum of the lengths of all sides) of a square is "40 cm." Since a square has 4 sides of equal length:
Each side is: 40 cm / 4 = 10 cm.
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