n= height of window
n+3 = width of window
2 (n+n+3) =38 (2 times the sum of the two different sides is the same as the perimeter)
2(2n+3) = 38
4n+6 = 38 (I combined like terms)
4n = 32 = (I subtracted 6 from both sides of the equation)
n=8 (I divided both sides by 4)
n=8 and n+3 = 11
Check If the two sides are 8 and 11 then 1/2 way around the rectangle is 8+11=19 and all the way around is twice that or 38.