A degree is a unit of measurement used to measure angles and temperature. In geometry an angle is measured in degrees with a full circle equaling 360°. Degrees are also used to measure temperature where water freezes at 0°C and boils at 100°C. It is essential in various fields of mathematics.

This chapter focuses on lines and angles. A line extends infinitely in both directions while an angle is formed when two rays meet at a common endpoint. Types of angles include acute right obtuse and straight. Understanding these concepts is essential for solving geometric problems and constructing shapes.