Question 332039
x= side of original square

rectangle formed Length=x+8, Width=x-2
Perimeter = 2*Length + 2Width or  
Perimeter/2=Length + Width

so...
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Perimeter/2=Length + Width
40/2= (x+8)+(x-2) = 2*x+6

20-6 = 2x
7=x