To locate √10 on number line follow the steps.                let 3cm = 1 unit
1] √10 = √3²+1²
2]draw a number line OC such that OA=AB=OC=1 unit
3] draw a perpendicular line from C of 1 unit [as √10 = √3²+ ] and name the point as C
4] join O and C  it will form a triangle 
       by pythagoras theorem  
           OC = √10
           now taking the radius of OC in compass draw an arc touching the number line . 
and that point will be   √10 .
can u show the calculations in all the right angles which are obtained