I am reading a book on Pattern Recognition (by Prof V Susheela Devi and Prof Murty) where in the chapter of data representation 2.3.3 the non metric similarity function is defined as those which do not obey either the triangular inequality or symmetry.
In that context, it further adds The squared Euclidean distance is itself an example of a non-metric, but it gives the same ranking as the Euclidean distance which is a metric.
Is the squared Euclidean distance different from the Euclidean distance?
How is the squared Euclidean distance non-metric?