Respuesta :

Leader
[tex] \sqrt{361} [/tex] = 19
This is because 19 X 19 = 361.

So the square root of 361 is 19.
erwin2h
This is mostly the remembering of square of number.
you can remember the easy way by

[tex]20^2=400[/tex]

which is greater than 361. 
Then you can reduce it to 19. And you will find out that

[tex]19^2=361[/tex]

so the answer is 19

Cheers :)