Answer:
13 ft
Step-by-step explanation:
Since you have memorized the squares of numbers up to 20, you know that ...
13² = 169
The area of a square is the square of its side length, so one side of Tasha's bedroom is 13 feet.
_____
If you haven't memorized those squares, you can use your calculator to find the square root of 169.
The formula for area of a square is ...
A = s²
Taking square roots, we have ...
s = √A
s = √169 = 13 . . . . feet