Coplanar lines : The lines that lie in the same plane are said to be coplanar lines, otherwise they are called non. coplanar lines. Same holds good for coplanar points (i.e.. points that lie in the same plane) and non-coplanar points, (Points that not lie in the same plane.) Points to remember : - Three or more points lying on the same line are called collinear points. - Only one line can be drawn through any two given points. - Two line can intersect maximum at one point. - If two different lines are perpendicular to a third line, then the former are parallel to each other, as shown below. m, B Here. m, 1. AB and m, 1 AB. Hence, as per above rule m, Ilm, - There are infinite number of points on a straight line. - Infinite number of lines can be made from a single point