# What Types of Angles There Are

An angle is formed from 2 rays or lines that share a common endpoint. There are different types of angles based on measurements or rotations, including obtuse, right, reflex, straight, positive, negative, and more.

**5-Minute Crafts** will help you figure out how to tell these different angles apart.

**I. Types of angles based on measurement**

### Acute angle

An acute angle is an angle that is **less than 90°**. It’s formed when 2 rays or lines intersect at a vertex. For example, 20, 30, 45, and 60-degree angles are considered acute.

### Right angle

It’s also known as** 90° angle**. The right angle is formed when 2 straight lines or rays are perpendicular to each other at the intersection (the angle between them equals exactly 90°). If you want to represent this angle as a symbol, use “∟.”

### Obtuse angle

An obtuse angle is an angle that is **greater than 90° but less than 180°**. For example, 100, 130, 145, and 165-degree angles are obtuse ones.

### Straight angle

It is also known as a **flat**** angle** and represents a **straight**** line**. If the angle formed between 2 rays is exactly 180°, then it’s called a straight angle. It can be made up of 2 right angles of 2 rays that face opposite directions.

### Reflex angle

It is an angle that is **greater**** than 180° and less than 360°**.

200, 250, and 310-degree angles are considered reflex angles. For example, in an original circular pizza, if we cut a small slice (or 2) and remove them, then the remaining part of the pizza represents a reflex angle.

### Full rotation angle

A full rotation angle is **360°**. An arm of such an angle goes on a complete rotation. You also can say “doing a **360**,” which means spinning around completely, once.

**II. Types of angles based on rotation**

- Angles that are turned from the base
**in the anti-clockwise**direction are called**positive**. **Negative**angles are rotated from the base**in the clockwise**direction.