Hello!
The square root of 4 would be 2.
The square root of a number is a number that can be multiplied by itself to get that number. For example, 6 would be the square root of 36 because when you multiply 6 by itself (6*6) you will get 36. Same thing with 4. When you multiply 2 by itself (2*2) you'll get 4 as your answer.
So the square root of 4 is 2
I hope this helps!