# Lecture 1 Trigonometric Functions Class 11

It does not matter how slowly you go as long as you do not stop. – Confucius

# Lecture - 1 Chapter 3 Trigonometric Functions

Meaning and origin of Word Trigonometry

Basics of Angles: Positive angles, negative angles, vertex with animations

Measuring an angle

Basics of Degree measure, minutes and seconds

Basics of Radian measure with animation

Relation between degree measure and radian measure

 NCERT Exercise 3.1

1. Find the radian measures corresponding to the following degree measures:
(i) 25°
(ii) – 47°30′
(iii) 240°
(iv) 520°