A line is a straight one-dimensional figure that extends infinitely in both directions. It has no thickness or width. A line can be represented by two points or using an arrow to show its infinite length. Lines are fundamental in geometry and used to define angles and shapes.

In this chapter students learn about lines and angles. A line is a straight path that extends infinitely in both directions. Angles are formed when two rays meet at a common point. Types of angles include acute right obtuse and straight. Understanding these concepts is key to solving geometric problems.