Assuming you mean how many square yards in 19 sq ft:1 sq yd = 1 yd x 1yd= 3 ft x 3 ft= 9 sq ft⇒ divide by 9 to convert square feet to square yards⇒ 19 sq ft = 19 ÷ 9 sq yds= 21/9 sq yds~= 2.11 sq yds
12' * 21 ft = 12*21 sq ft = 252 sq ft.
1386 sq ft
12 ft * 19 ft = 12*19 sq ft = 228 sq ft = 25.33.. sq yards
21-ft x 3-ft = 63 ft2
Assuming you mean how many square yards in 19 sq ft:1 sq yd = 1 yd x 1yd= 3 ft x 3 ft= 9 sq ft⇒ divide by 9 to convert square feet to square yards⇒ 19 sq ft = 19 ÷ 9 sq yds= 21/9 sq yds~= 2.11 sq yds
12' * 21 ft = 12*21 sq ft = 252 sq ft.
1386 sq ft
12 ft * 19 ft = 12*19 sq ft = 228 sq ft = 25.33.. sq yards
21 x 21 = 441 sq in or 3.06 sq ft
19 x 19 = 361 sq ft
98 ft x 19 ft = 1862 ft2 (sq ft)
21-ft x 3-ft = 63 ft2
21 ft * 6 ft = 126 sq ft = 11.7 sq metres approx.
19-ft x 10-ft = 190 ft2 = 17.652 meter2 (rounded)
Top = 5 x 3 = 15 sq ft Bottom = 5 x 3 = 15 sq ft 2 sides = 5 x 7 = 35 sq ft each other 2 sides = 3 x 7 = 21 sq ft each Total cardboard = 142 square feet Surface area = 142 sq ft inside, and 142 sq ft outside.
Answer = 21 ft x 13 ft = 273 sq feet