Final answer:
To calculate the side length of Kenneth's square wallpaper, you take the square root of the area, which is 45.2 ft². The square root of 45.2 is approximately 6.723, making the closest approximation of the side length 6.7 ft (option A).
Step-by-step explanation:
The question asks us to find the side length of a square piece of wallpaper given its area. To find this length, we must understand that the area of a square is calculated by squaring its side length, meaning side length x side length = area. Therefore, to find the side length, we need to take the square root of the area.
For Kenneth's wallpaper, the area is 45.2 ft². The square root of 45.2 is approximately 6.723. Among the given options, the closest approximation to the side length is 6.7 ft, which makes option A the correct answer: A. 6.7 ft.