In this video you will learn about the topics basic terms and definitions of the chapter lines and angles.
- Collinear Points: Three or more points are said to be collinear, if a line passes through all three points.
- Ray: Ray is a part of line, which has one the end point and can be extended indefinitely on the other end.
- When two rays have a common initial point they are said to have formed an angle.
- The angle is measured in degrees or radians.
- Acute angle: If the measure of an angle lies between 0o and 90o.
- Right angle: If the measure of an angle is equal to 90o.
- Obtuse Angle: If the measure of an angle lies between 90o and 180o.
- Straight angle: If the measure of an angle is equal to 180o.
- Reflex angle: If the measure of an angle is greater than 180o but less than 360o.
CBSE Class 9: Heron’s Formula - Applications of Heron’s Formula
CBSE Class 9: Lines and Angles - Types of Angles