It is nine square feet.
36 in x 36 in = 3 ft x 3 ft = 9 sq ft
There are 144 square inches per square foot; so multiply by 144. 36 sq ft X 144 sq in / sq ft = 5184 sq inches
Assuming the question is about 36 inches x 78 inches= 36/12 feet * 78/12 feet= 3 ft * 6.5 ft* 19.5 sq ft.
30 inches x 72 inches = 2.5 ft * 6 ft = 15 sq ft.30 inches x 72 inches = 2.5 ft * 6 ft = 15 sq ft.30 inches x 72 inches = 2.5 ft * 6 ft = 15 sq ft.30 inches x 72 inches = 2.5 ft * 6 ft = 15 sq ft.
Each of your pieces is (6 X 36) sq. in. or 216 sq in. There are 144 sq. in. in a sq. ft. SO, each piece is (216/144) sq. ft. or 1.5 sq. ft. So, you would need (225 sq. ft./1.5 sq. ft. per plank) or 150 planks.
12" = 1 foot 36" = 3 ft 36" x 36" = 9 sq ft 1,098 sq ft/9 sq ft per tile = 122 tiles
12 in = 1 ft ⇒ 26 in x 38 in = (26 ÷ 12) ft x (38 ÷ 12) ft = 631/36 sq ft ≈ 6.86 sq ft
1 ft = 12 inches. 1 square foot = 1 ft x 1 ft = 12 inches x 12 inches = 12*12 sq inches = 144 sq inches.
You can multiply them as mixed fractions, or convert both to inches, then divide by 144 (sq in / sq ft). 9 ft = 108 in, add 7 in = 115 in. 3 ft = 36 in, add 6 in = 42 in. Multiply (115 in) x (42 in) = 4830 sq in. Divide by 144 (sq in/sq ft) = 33.541667 sq ft.
12 in = 1 ft ... (36/12) X (24/12) = 3 X 2 = 6 sq ft
1 ft = 12 inches 1 sq ft = 12 x 12 = 144 sq in 10 sq ft = 10 x 144 = 1440 sq in
3 square feet = 3 ft x 1 ft = 36 in x 12 in = 432 sq in