Lines and Angles

About this chapter

Lines and Angles is Chapter 2 of Class 6 Ganita Prakash. It lays the foundation of plane geometry by building the basic objects that all later geometry depends on. The chapter develops seven core ideas: a point as a precise location with no length, breadth or height; a line segment as the shortest path between two endpoints; a line that extends without end in both directions; a ray that starts at one point and goes on endlessly in one direction; an angle formed by two rays sharing a common vertex, with size measured as the amount of rotation between the arms; classifying angles as straight (180°), right (90°), acute (<90°), obtuse (between 90° and 180°) and reflex (between 180° and 360°); and measuring or drawing angles in degrees using a protractor, with the angle bisector cutting an angle into two equal halves. CTET Paper 2 Mathematics tests this chapter through naming rays, counting segments, classifying angles by measure, reading a protractor and spotting the arm-length misconception. The four tests below cover these ideas at the right depth.