# Different Types of Angles

An angle is formed when two rays or lines intersect at the same point. Measurements show several geometry angles, including zero angles, acute, obtuse, right angles, reflex angles, and straight angles. We use angles to construct buildings, roads, dams, cars, etc.

From a slice of pizza to woodworking sketches and fashion designs, you can find angles everywhere. It also uses the concept of angles to measure changes in the trajectory of ships, airplanes, planetary objects, etc. Let's look at the seven types of angles, their properties, and how to measure them.

## What are the seven types of angles based on measurements?

The space created when two rays or lines meet at the same point is called an angle. Angles can be classified according to their measurements and how they are rotated. Based on the measurement, there are seven types of angles.

### 7 Types of angles

### Acute angles

Any angle less than 90° is an acute angle. An acute angle is formed when two rays intersect at a vertex to form an angle of less than 90°. Some examples of acute angles: are 20°, 30°, 45°, and 60°. Note the figure that shows that the angle ∠ABC is acute.

#### Right Angle

If the angle between the two rays or lines is exactly 90°, it is said to be a right angle or 90°. From the figure, you can see that ∠ABC is a right angle or 90°.

### Obtuse Angle

Any angle greater than 90° and less than 180° is an obtuse angle. In the figure, the angle between the lines XY and YZ is obtuse. Some examples of obtuse angles: are 110°, 130°, 145°, and 165°.

### Straight Angles

As the name suggests, a right angle is a straight line, and the angle between the two rays is exactly 180°. At right angles, the two beams are opposite each other. A right angle can be made by connecting two adjacent right angles. That is, two right angles make up a right angle. In the figure, ∠ABC stands for 180° or **straight angle**.

### Reflex Angle

Angles more significant than 180° and less than 360° are called reflex angles. In the figure, ∠ABC is the angle of reflection. Examples of reflection angles: 210°, 250°, 310°.

### Full Rotation Angle

A whole rotation angle is formed when one of the arms rotates completely or makes 360°. In the figure, the angle is called the full rotation angle.

### Different Types of angles based on Rotation:

The following angles are based on the direction of rotation of one arm of an angle. An angle is formed when two lines intersect and meet at the same point. Let's discuss the types of angles based on rotation.

### Positive Angles

A positive angle is an angle that rotates counterclockwise or anti-clockwise from the reference. In the figure below, turning side 1 (AB) counterclockwise through angle θ produces a positive angle.

### Negative Angles

A negative angle is one in which the angle rotates clockwise from the base. In the figure below, turning sidewise through angle θ produces a negative angle.

### Types Of Angles Pairs

An angle pair represents two angles. Let's read about the various pairs of angles in geometry.

### Adjacent angles

For two edges to be a part of **adjacent angles**, the following conditions must be met:

- Both edges have a common vertex.
- Both edges have a common shoulder.
- The angles must not overlap.

Here angle a and angle b are adjacent angles.

### Complementary Angle

Two angles are said to be complementary when the sum of the two angles is 90°. The two angles can be of any size so that the sum of them is up to 90°. For example, the two angles could be 30° and 60°. Here, one angle is the complement of the other.

### Supplementary Angles

When the sum of two angles is 180°, the two angles are said to be supplementary. The two angles add up to 180°. For example, 110° and 70° are 180°. Therefore, these two angles are called supplementary angles. Here, one angle is the supplement of the other. For example, the supplement of 60° is (180° 60°) which is 120°.

### Alternate interior angles

When a line or secant passes through two parallel lines, the angle formed on opposite sides of the line or secant is called a parallel interior angle and is equal.

### Alternate exterior angles

When a line or secant passes through two parallel lines, the angle formed on the outside of the line or secant alternately is called the equivalent exterior angle.

### Corresponding angles

When a straight line or a secant passes through two parallel lines, the angles formed at the same location or on the same side of the secant are corresponding angles and are equal.

### Vertical angles

When two lines intersect each other, the angles facing each other are equal, so they are called perpendicular or perpendicular opposite angles.