The window has a shape of a quadrilateral which has a higher length than width. So, this is a rectangular window. The area of a rectangle is equal to its length time width. Since l = 6w,
lw = 315
6w*w = 315
6w² = 315
w² = 315/6
w² = 52.5
w = √52.5
w = 7.25 inches
Consequently, l = 6w = 6*7.25 = 43.5 inches.
Thus, the window has a length of 43.5 inches and a width of 7.25 inches.