Angle:

An angle consists of two rays, R1 and R2, with a common vertex.

 

Standard position of an angle:

An angle is said to be in standard position if its vertex is at the origin of a rectangular coordinate system and its initial side coincides with the positive x-axis.

 

Co-terminal angles:

Two angles in standard position are said to be co-terminal if they have the same initial and terminal sides.

 

Arc length:

For a circle of radius , a central angle of  radius subtends and arc whose length is

.

 is measured in radians.

Area of a sector:

The area of the sector of a circle of radius formed by a central angle  radians is

 where the unit of angle  must be in radians.

Flash Movie	Flash Game	Flash Card
Core Concept Tutorial	Problem Solving Drill	Review Cheat Sheet

This tutorial starts with the unit circle in introducing trigonometric functions. It covers angles and the relation of angles with respect to radians and trigonometric functions. The angle measure is represented in different ways as it is shown in the examples. The properties of angles are mentioned along with their use in trigonometry problems.  Arc length and area of a sector are also discussed.

 

Specific Tutorial Features:
• Example problems with step by step solutions and accompanying diagrams to help illustrate the usage of angles in finding the values of trigonometric functions.

Series Features:
• Concept map showing inter-connections of new concepts in this tutorial and those previously introduced.
• Definition slides introduce terms as they are needed.
• Visual representation of concepts
• Animated examples—worked out step by step
• A concise summary is given at the conclusion of the tutorial.

The unit circle
Radian and degree angle measures
Positive and negative angles
Complementary and supplementary angles
Arc length and area of sectors