Square Root of:
4 = 2
9 =3
16=4
25=5
36=6
49=7
64=8
81=9
100=10
121=11
144=12
169=13
Just memorize, or make sure that it is a perfect square. If not, example. Square root of 20. You have to find a perfect square and multiply it, square root of 4x5. 4 is perfect square so the square root of 20 is 4 square root of 5.
