12 ft * 20 ft = 240 sq ft
5 ft * 5 ft = 25 sq ft
So
12 ft * 20 ft minus 5 ft * 5 ft = 240 sq ft - 25 sq ft = 215 sq ft
-5 + (-4) - 12 - 20 - (-10) + 6 = -25
multiply feet by 12 and add inches; then minus inches. Example: 2 feet 2 inches minus 5 inches = 26-5 = 21 inches
5" is less than 1 foot.
Area = 1/2*(12+20)*5 = 80 square feet
Area = 1/2*(12+20)*5 = 80 square feet
13 feet 7 inches......
It is: 5/12 minus 3/20 = 4/15
12 feet 3 inches minus 4 feet 5 inches equals 7.83333333 feet or 7 feet 10 inches.
3/5 - 3/4 = 12/20 - 15/20 = (12 - 15)/20 = -3/20
That leaves you with just six inches.
3/5 - 1/4 = 12/20 - 5/20 = 7/20.
7 and 4/5 feet