October 04, 2022

Linear Pair of AnglesDefinition, Axiom, Examples

The linear pair of angles is an essential concept in geometry. With several real-world applications, you'd be amazed to figure out how useful this figure can be. Even though you may think it has no relevant 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 introductory insight into the properties of a linear pair of angles, with images and examples to assist with your personal study sessions. We will also discuss some real-life and geometric uses.

What Is a Linear Pair of Angles?

Linearity, angles, and intersections are ideas that continue to be relevant as you move ahead with geometry and more complex theorems and proofs. We will answer this query with a easy definition in this single point.

Explanation

A linear pair of angles is the term provided to two angles that are located on a straight line and have the sum of their measurement of angles is 180 degrees.

To put it easily, linear pairs of angles are two angles that sit on the same line and together form a straight line. The sum of the angles in a linear pair will at all times make a straight angle equivalent
times to 180 degrees.

It is crucial to note that linear pairs are always at adjacent angles. They share a common vertex and a common arm. This suggests that they always form on a straight line and are always supplementary angles.

It is essential to explain that, even though the linear pair are at all times adjacent angles, adjacent angles aren't always linear pairs.

The Linear Pair Axiom

Over the precise explanation, we will examine the two axioms seriously to completely comprehend any example thrown at you.

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

The first axiom states that if a ray stands on a line, the adjacent angles will form a straight angle, making them 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 among them. This is also known as a straight line.

Examples of Linear Pairs of Angles

To visualize these axioms better, here are a few diagram examples with their individual answers.

Example One

Here in this example, we have two angles that are next to each other. As you can observe in the diagram, the adjacent angles form a linear pair because the total 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 possess two lines intersect, producing four angles. Not every angles creates a linear pair, but respective angle and the one next to it makes a linear pair.

∠A 30 degrees

∠B: 150 degrees

∠C: 30 degrees

∠D: 150 degrees

In this case, the linear pairs are:

∠A and ∠B

∠B and ∠C

∠C and ∠D

∠D and ∠A

Example Three

This instance represents a common point of three lines. Let's observe the axiom and characteristics of linear pairs.

∠A 150 degrees

∠B: 50 degrees

∠C: 160 degrees

None of the angle combinations sum up to 180 degrees. As a consequence, we can come to the conclusion that this diagram has no linear pair unless we expand one straight line.

Applications of Linear Pair of Angles

Now that we have gone through what linear pairs are and have looked at some instances, let’s understand how this theorem can be used in geometry and the real-life scenario.

In Real-Life Scenarios

There are many uses of linear pairs of angles in real life. One familiar example is architects, who apply these axioms in their day-to-day work to determine if two lines are perpendicular and creates a straight angle.

Builders and construction professionals also employ experts in this matter to make their job easier. They utilize linear pairs of angles to make sure that two close walls form a 90-degree angle with the floor.

Engineers also apply linear pairs of angles frequently. They do so by figuring out the tension in beams and trusses.

In Geometry

Linear pairs of angles as well perform a role in geometry proofs. A common proof that uses linear pairs is the alternate interior angles concept. This theorem explains that if two lines are parallel and intersected by a transversal line, the alternate interior angles made are congruent.

The proof of vertical angles additionally replies on linear pairs of angles. Although 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 previously mentioned two rules, you are only required to determine the measurement of one angle to figure out the measure of the rest.

The theorem of linear pairs is subsequently used for more sophisticated uses, such as figuring out the angles in polygons. It’s essential to grasp the basics of linear pairs, so you are prepared for more progressive geometry.

As you can see, linear pairs of angles are a comparatively easy concept with some interesting uses. Next time you're out and about, observe if you can spot any linear pairs! And, if you're participating in a geometry class, bear in mind how linear pairs might be helpful in proofs.

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