October 04, 2022

Linear Pair of AnglesDefinition, Axiom, Examples

The linear pair of angles is a significant subject in geometry. With multiple real-life functions, you'd be astonished to figure out how useful this figure can be. Even though you might believe it has no application in your life, we all should grasp the concept to nail those exams in school.

To save your time and create this information easily accessible, here is an preliminary insight into the properties of a linear pair of angles, with images and examples to help with your personal study sessions. We will also discuss some real-world and geometric uses.

What Is a Linear Pair of Angles?

Linearity, angles, and intersections are theories that continue to be relevant as you progress in geometry and more sophisticated theorems and proofs. We will answer this query with a straightforward explanation in this unique point.

Definition

A linear pair of angles is the name designated to two angles that are situated on a straight line and have the sum of their angles measure 180 degrees.

To put it easily, linear pairs of angles are two angles that are aligned on the same line and together create a straight line. The total of the angles in a linear pair will at all times produce a straight angle equal to 180 degrees.

It is essential to bear in mind that linear pairs are always at adjacent angles. They share a common apex and a common arm. This suggests that at all times form on a straight line and are at all times supplementary angles.

It is important to clarify that, while the linear pair are always adjacent angles, adjacent angles not at all times linear pairs.

The Linear Pair Axiom

With the definition simplified, we will explore the two axioms seriously to completely comprehend every example thrown at you.

Initiate with definition of what an axiom is. It is a mathematical postulate or assumption that is accepted without having to prove; it is considered obvious and self-explanatory. A linear pair of angles has two axioms connected with them.

The first axiom states that if a ray is located on a line, the adjacent angles will make a straight angle, namely called a linear pair.

The second axiom establishes that if two angles produces a linear pair, then uncommon arms of both angles create a straight angle between them. This is also known as a straight line.

Examples of Linear Pairs of Angles

To imagine these axioms better, here are a few diagram examples with their corresponding explanations.

Example One

As we can see in this instance, we have two angles that are next to one another. As you can notice in the diagram, the adjacent angles form a linear pair due to the fact that the sum of their measures equals 180 degrees. They are also supplementary angles, since they share a side and a common vertex.

Angle A: 75 degrees

Angle B: 105 degrees

Sum of Angles A and B: 75 + 105 = 180

Example Two

Here, we have two lines intersect, making four angles. Not every angles makes a linear pair, but respective angle and the one adjacent to it form a linear pair.

∠A 30 degrees

∠B: 150 degrees

∠C: 30 degrees

∠D: 150 degrees

In this instance, the linear pairs are:

∠A and ∠B

∠B and ∠C

∠C and ∠D

∠D and ∠A

Example Three

This example presents convergence of three lines. Let's look at the axiom and properties of linear pairs.

∠A 150 degrees

∠B: 50 degrees

∠C: 160 degrees

None of the angle totals sum up to 180 degrees. As a result, we can conclude that this example has no linear pair until we stretch one straight line.

Uses of Linear Pair of Angles

At the moment we have explored what linear pairs are and have looked at some cases, let’s check how this concept can be utilized in geometry and the real world.

In Real-Life Situations

There are multiple utilizations of linear pairs of angles in real-world. One common example is architects, who utilize these axioms in their daily work to establish if two lines are perpendicular and form a straight angle.

Construction and Building professionals also employ expertise in this field to make their work easier. They use linear pairs of angles to assure that two adjacent walls make a 90-degree angle with the floor.

Engineers also uses linear pairs of angles frequently. They do so by calculating the weight on the beams and trusses.

In Geometry

Linear pairs of angles additionally play a role in geometry proofs. A ordinary proof that utilizes linear pairs is the alternate interior angles concept. This theorem expresses that if two lines are parallel and intersected by a transversal line, the alternate interior angles formed are congruent.

The proof of vertical angles as well depends on linear pairs of angles. Even though the adjacent angles are supplementary and sum up to 180 degrees, the opposite vertical angles are at all times equivalent to each other. Because of above-mentioned two rules, you only need to determine the measure of any one angle to figure out the measure of the rest.

The concept of linear pairs is subsequently used for more sophisticated implementation, such as measuring the angles in polygons. It’s important to grasp the fundamentals of linear pairs, so you are prepared for more progressive geometry.

As shown, linear pairs of angles are a comparatively easy theorem with few fascinating implementations. Later when you're out and about, take note if you can notice any linear pairs! And, if you're taking a geometry class, take notes on how linear pairs might be helpful in proofs.

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