Question

What is the square root of 169?

Answer 1

13

Explanation:

The answer is 13

Answer 2

`169 = 13`

This is the principal root.
The root can be `+-13`

Explanation:

We are looking for a number which, multiplied by itself makes 169.

`x^2 = 169`

It is a huge advantage in your Maths to know all the squares up to `20^2` by heart.

`12^2 =144`
`13^2 = 169`

Bu estimating....

`10^2 = 100 and 20^2 = 400`

So, `sqrt169` lies between 10 and 20.
If you find it by estimating, the number 9 at the end means that the square root must end in a 3 or a 7.

The only options are `13^2 and 17^2`
Multiplying gives `13^2 = 169 and 17^2 = 289`