Lines and Angles
Class 9 · Mathematics · 5 lessons
This chapter, Lines and Angles, is part of the Class 9 Mathematics syllabus under CBSE, Telangana and Andhra Pradesh boards. It contains 5 lessons — starting with Introduction to Lines and Angles, Exercise 4.1 — Lines and Angles Basics, Exercise 4.2 — Pairs of Angles, and more — each with free, step-by-step PDF notes you can study directly in the browser or present in class in fullscreen mode. Work through the lessons in order below; later exercises in this chapter generally build on the concepts introduced in the earlier ones.
Introduction to Lines and Angles
Basic terms of geometry, intersecting lines and concurrent lines.
Exercise 4.1 — Lines and Angles Basics
Simple problems based on lines and angles.
Exercise 4.2 — Pairs of Angles
Pairs of angles and angles in intersecting lines.
Exercise 4.3 — Parallel Lines
Lines and a transversal, lines parallel to the same line.
Exercise 4.4 — Angle Sum of Triangle
Angle sum property of a triangle.