# What's the square root of 20?

Jul 29, 2015

$\sqrt{20} = 2 \sqrt{5}$

#### Explanation:

$\sqrt{20}$

Factor 20 into its prime factors.

$\sqrt{2 \times 2 \times 5}$ =

$\sqrt{{2}^{2} \times 5}$

Apply rule $\sqrt{{a}^{2}} = a$

$2 \sqrt{5}$