Answer:
The first step to do is trying to find the closest perfect square less than 845, and the closest perfect square more than 845.
In this case 29^2 (841) is the closest perfect square less than 845, and 30^2 (900) is the closet perfect square more than 845.
In conclusion we will say that 29 < √ 845 < 30.
Hope it helps you.