HomeNCERT 9 Mathematics LINES AND ANGLES RK Yadav -February 20, 2017 0 Chapter: 6 LINES AND ANGLESLINEA line has length but no width and no thickness.ANGLEAn angle is the union of two non-collinear rays with a common initial point. The common initial point is called the ‘vertex’ of the angle and two rays are called the ‘arms’ of the angles. Tags: NCERT 9 Mathematics NCERT 9 Maths ncert maths for class 9 Facebook Twitter