Calculating the distance between 2 points

Question

I have two points (x1,y1) and (x2,y2). I want to know whether the points are within 5 meters of one another.

Answer 1

Given points (X1,Y1) and (X2,Y2) then:

dX = X1 - X2;
dY = Y1 - Y2;

if (dX*dX + dY*dY > (5*5))
{
    //your code
}