Answer:
40 square meters
Step-by-step explanation:
The area of the floor is 64 square meters. That means the square is 8 meters by 8 meters. Each side of the floor is 8 meters. Now a wall has an 8 meter side along the floor and a height of 5 meters. Each wall is a rectangle 8 m x 5 m with an area of 8 x 5 = 40 square meters.
