## THREE-DIMENSIONAL GEOMETRY​

 Direction cosines/ratios of a line joining two points. Direction cosines/ratios of a line joining two points. Straight lines in space Cartesian and vector equation  of a line  passing  through  given point and parallel to given vector, Cartesian and vector equation of aline  passing through two  given  points, coplanar and skew lines,  distance between two skew lines(Cartesian and vector approach),  distance between two parallel lines (vector  approach). Angle between two lines. Problems related to above concepts. Plane Cartesian and vector equation of  a plane in normal form, equation of  a plane passing through the given point and perpendicular to given vector,  equation of  a plane  passing  through  three  non- collinear points,  Intercept form of  equation of a plane, angle  between  two planes,  equation of plane passing through  the   intersection  of  two  given planes,   angle   between line  and  plane, condition for the coplanarity  of  two  lines,  distance   of   a point from a  plane (vector  approach) ,Problems related to above concepts.