Here,17=42+1
So, draw a right angled ΔOAB, in which OA = 4 units and AB = 1 unit and ∠OAB=90∘
By using Pythagoras theorem, we get OB=√OA2+AB2=√42+12=√16+1=√17
Taking OB=√17 as radius and point O as centre, draw an arc which meets the number line at point P on the positive side of it. The point P represents √17 on the number line.