Final answer:
The total area of all four walls in a square room with a floor area of 81 ft² and a height of 10 feet is 360 ft². This is calculated by finding the side length of the room, which is 9 feet, and then multiplying the length by the height of the room to get the area of one wall, and finally multiplying by four for all four walls.
Step-by-step explanation:
To calculate the total area of all four walls of a square room with a floor area of 81 ft² and a height of 10 feet, we first need to find the length of one side of the square room. Since the area of a square is equal to the side length squared (s²), and the floor area is 81 ft², we can find the length of one side of the room by taking the square root of 81, which is 9 feet. Therefore, each side of the room is 9 feet long.
Next, to find the area of one wall, we multiply the side length by the height of the room: 9 feet × 10 feet = 90 ft² per wall. Since there are four walls in a room and each wall has the same area, we multiply the area of one wall by four: 90 ft² × 4 = 360 ft². Hence, the total area of all four walls is 360 ft².