Cartesian coordinate system

How to find distance between two points

Let’s Consider A, B two point and their coordinate respectively (x1, y1) ,(x2, y2)

 ALMN   

AN = LM=|OM-OL|=| x2 - x1|

          BN = |BM-NM| =|BM-AL|=| y2 - y1|

ANB 

From Pythagoras thermo;

    

So using above equation can find distant between two points

Example

If A (5, 2) ,B (1,-1) then find distance between AB