### Mathematics Class XI

Unit-I: Sets and Functions
Chapter 1: Sets
Unit-II: Algebra
Chapter 5: Binomial Theorem
Chapter 6: Sequence and Series
Unit-III: Coordinate Geometry
Chapter 1: Straight Lines
Chapter 2: Conic Sections
Unit-IV: Calculus
Unit-V: Mathematical Reasoning
Unit-VI: Statistics and Probability
Chapter 1: Statistics
Chapter 2: Probability

# Angles

Angle is a measure of rotation of a given ray about its initial point. The original ray is called the ‘initial side’ and the final position of the ray after rotation is called the ‘terminal side’ of the angle. The point of rotation is called the ‘vertex”. If the direction of rotation is anticlockwise, the angle is said to be positive and if the direction of the rotation is clockwise, then the angle is negative. The measure of an angle is the amount of rotation performed to get the terminal side from the initial side. The definition of an angle suggests a unit, i.e., a complete revolution from the position of the initial side to the terminal side.

The measurement of an angle which are most commonly used, i.e., degree measure and radian measure.

Scroll to Top