Probably a wall of some sort.
19 feet squared = 361 square feet.
I don't understand why there are so many questions which seem to show no understanding of the difference between square feet, a measure of area, and linear feet, a measure of length. The deck has an area of 304 square feet.
3 feet by 19 feet = 3 * 19 = 57 square feet.
8 feet by 19 feet = 152 square feet.
There are: 12*19 = 228 square feet
19 x 13 = 247 square feet.
20 x 19 = 380 square feet.
26 feet x 19 feet = 494 square feet.
19 feet by 28 feet gives you 532 square feet.
To calculate the square footage of a room that is 19 feet by 19 feet, you would multiply the length by the width. In this case, 19 feet multiplied by 19 feet equals 361 square feet. Therefore, the room is 361 square feet in total area.
To calculate the square footage of a rectangle, you simply multiply the length by the width. In this case, 19 feet by 20 feet would be 380 square feet. This is because 19 feet multiplied by 20 feet equals 380 square feet.
26 feet x 19 feet = 494 square feet.