Question

How do you find the square root $20$?

Answer 1

Find the square root using prime factorization method:

The prime factors of $20$ are

$20=2\times 2\times 5$

Therefore the square root of $20$ is

$\begin{array}{rcl}20& =& 2\times 2\times 5\\ & \Rightarrow & \sqrt{20}=\sqrt{2\times 2\times 5}\\ & \Rightarrow & \sqrt{20}=2\sqrt{5}\end{array}$

Hence, the square root of $\mathbf{20}$ is $\mathbf{2}\sqrt{\mathbf{5}}$.