What is the square root of 0.785 rounded

The square root of any number: square root of 100 is ten because its ten times itself equals 100. See how to do it? 

Now onto the question, we're trying to find the square root of: 0.785

Well, it is: .8860022573  
But in shorter terms, meaning when rounded, Our answer will come out to be

12+3b -1=-5-b -12-1+5=-b-3b -8=-4b