Types of Angles in Pair

Angles Formed by Transversal and Parallel Lines

There are five types of angles on the basis of pairs. They are:

Complementary Angles

If the summation of two angles measures 90° then, the angles are said to be Complementary Angles and each angle is called a complement of the other.

The two angles combining together do not require to be adjacent or similar. It can be any two types of angles measuring 90° after addition. For Example, 70 and 20 are complementary angles.

Supplementary Angles

If the summation of two angles measures 180°, the angles are said to be Supplementary Angle. Each Angle is called a Supplement of the other.

For Example, 150° and 30° are Supplementary Angles.

Adjacent Angles

Two angles are said to be adjacent if they have a common vertex, a common arm, and the rest two arms lie on the alternate side of the common arm. Angle AOC and Angle BOC are Adjacent Angles

∠AOC and ∠BOC are here adjacent because they have a common point O, a common vertex OC and rest two arms OA and OB lie on the alternate side of the common arm.

Linear Pair

When the sum of two adjacent angles is 180° then they are called a Linear Pair.

As the name suggests the pair of angles result in a straight line.

Remember that there is one difference between Supplementary Angle and Linear Pair. For Linear Pair, the two angles must be adjacent while there is no such condition for Supplementary Angles. For Supplementary Angles, only the sum of the angles should be 180° doesn’t matter if they are adjacent or not.

Here ∠AOC and ∠BOC are linear pairs as AOB is a straight line.

Vertically Opposite Angles.

When two lines intersect each other at a common point then the pair of angles in front of each other are called Vertically Opposite Angles.

In the below figure, AB and CD are two lines that intersect each other at O, then pairs of Vertically Opposite Angles are (∠AOC, ∠BOD) and (∠AOD, ∠BOC).
It should be noted that a pair of vertically opposite angles are equal i.e. ∠AOC = ∠BOD) and ∠AOD = ∠BOC).

Angles Definition, Types and Examples

An angle is a figure which is formed by two rays or lines that share a common endpoint is called an angle. The word “angle” is derived from the Latin word “angulus”, which means “corner”. The two lines joined together are called the arms of the angle and the measure of the opening between them is the value of the angle between these two lines.

In this article, we will learn about the definition and parts of angles in Geometry, their representation, examples, and types like acute angle, right angle, obtuse angle, etc. along with FAQs.

Table of Content

Angle Definition
Parts of an Angle
Types of Angles
Types of Angles Based on Measurement
Positive and Negative Angles
Types of Angles in Pair
How to Measure an Angle?
Steps to Construct an Angle