Answer:
x = 10 feet
Step-by-step explanation:
Given that,
The area of his bathroom is 100 square feet.
We need to find the one side of the square bathroom.
Let the side be x. The area of a square is given by :
[tex]A=x^2\\\\100=x^2\\\\x=10\ \text{feet}[/tex]
So, the side of the square bathroom is 10 feet.