### Introduction to Angles and Types of Angles

Angles are formed by the intersection of two lines. Lets us start with the learning of Introduction to Angles and Types of Angles.

## Introduction to Angles

When two lines intersect, at the point of their intersection an angle is formed. The two rays that form the angle are known as the sides of the angle. Also, it is not necessary that an angle is formed by the intersection of two straight lines; it can be formed by the intersection of two curved lines too.

### The parts of an angle are

Vertex – Point where the arms meet
Arms – Two straight line segments from a vertex
Angle – If a ray is rotated about its end-point, the measure of its rotation is called angle between its initial and final position

### Type of angles

1. Acute angle
2. Right angle
3. Obtuse angle
4. Straight angle
5. Reflex angle
6. Full angle

### Acute angle:

An angle which measures lie between 0 to 90 is called a acute angle.

### Right angle:

An angle which measures exactly 90 is called a right angle.

### Obtuse angle:

An angle which measures lie between 90 to 180 is called a obtuse angle.

### Straight angle:

An angle which measures exactly 180 is called a straight angle.

### Reflex angle:

An angle which measures lie between 180 to 360 is called a reflex angle.

### Full angle:

An angle which measures exactly 360 is called a right angle.

 Angle Description Acute Angle angle between 0 and 90 degrees Right Angle exactly 90 degrees Obtuse angle angle between 90 and 180 degrees Straight angle exactly 180 degrees Reflex angle angle between 180 and 360 degrees Full angle exactly 360 degrees

### Positive and Negative Angles

Positive angle: Angle measured counterclockwise from the base
Negative angle: Angle measured clockwise from the base