Question

What is the square root of $400$?

Answer 1

Determine the square root of $400$.

The square root of a number is the value that returns the original number when multiplied by itself.

Find the prime factors of $400$:

$400=2\times 2\times 10\times 10$

Take square root from both sides of the above equation:

$$\begin{gathered} \sqrt{400}=\sqrt{2\times 2\times 10\times 10} \\ \Rightarrow \sqrt{400}=20 \end{gathered}$$

Hence, the square root of $400$ is $20$.