16" overlap on each panel side 8" overlap on each panel top/bottom --- Front side --- 28" (44") wide 12' in 2 panels = 17'4 = 34'8 total length Corner: 42 x 30 = 74 x 46 --- Back side --- 56" (72") wide 15'4 in 3 panels = 23'4 = 46'8 total length Corner: 78 x 57 = 110 x 73 20' length: 72" / 72" / 44" / 44" / 8" or 74" / 74" / 46" / 46" 30' length will cover entire roof