What is the square root of 169?

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Answer 1 · 2015-09-13T03:13:22

13

The answer is 13

Answer 2 · 2016-08-31T11:31:09

$169 = 13$

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

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 $13^2 = 169 and 17^2 = 289$