I created Buffer (with Vector, Geoprocessing Tools) with 500 M distance from a point in the map (let's say Point A). I made another point (Point B) and it is not inside the 500 m Buffer. The Distance matrix tool shows that the points are separated about 413 M from each other. I noticed that this difference comes (using the Measure Line tool), because the buffer has Cartesian distance, yet the distance in Distance Matrix shows the ellipsoidal distance values.
How to either make the buffer in ellipsoidal distance, or let the distance matrix shows Cartesian distance?
Note: The Cartesian distance of point A and B is about 661 Meters for each other.