simplify $sqrt{169}$ using rational numbers.

Explanation:

Step1: Recall square - root definition

Find a number $x$ such that $x^2 = 169$.

Step2: Identify the number

We know that $13\times13=169$ and $(- 13)\times(-13)=169$. Since we are looking for the principal square - root (the non - negative square - root when the radical symbol $\sqrt{}$ is used), $x = 13$.

Answer:

$13$