1) Vertical angles are formed on opposite side at the intersection of two lines .In the given figure the angle vertical to OSN is LSM and hence they are vertical pair.
2) The pair of angles LSM and SMN are neither adjacent angles nor linear pair or vertical angles .Hence we can call them complementary angles.Complementary angles are one which add to 90 degrees.
3) The angle pair are NSM and MSL lie on a straight line and hence are called linear pair.
