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 surprised to find how relevant this figure can be. Although you may believe it has no use in your life, we all must understand the concept to nail those tests in school.

To save you time and make this data easy to access, here is an introductory insight into the properties of a linear pair of angles, with diagrams and examples to assist with your private study sessions. We will also discuss some real-world and geometric uses.

What Is a Linear Pair of Angles?

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

Explanation

A linear pair of angles is the term given 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 pair up to form a straight line. The sum of the angles in a linear pair will always make a straight angle equal 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 at all times create on a straight line and are always supplementary angles.

It is essential to explain 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 study the two axioms critical to completely understand every example thrown at you.

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

The first axiom implies that if a ray stands on a line, the adjacent angles will form a straight angle, namely called a linear pair.

The second axiom states that if two angles makes a linear pair, then uncommon arms of both angles makes a straight angle among them. In other words, they make a straight line.

Examples of Linear Pairs of Angles

To visualize these axioms better, here are some diagram examples with their individual explanations.

Example One

Here in this instance, we have two angles that are adjacent to each other. As you can see in the figure, the adjacent angles form a linear pair because the total of their measurement equals 180 degrees. They are also supplementary angles, because 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

In this instance, we have two lines intersect, producing four angles. Not all angles creates 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 example, the linear pairs are:

∠A and ∠B

∠B and ∠C

∠C and ∠D

∠D and ∠A

Example Three

This instance represents an intersection 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 combinations add up to 180 degrees. As a result, we can conclude that this diagram has no linear pair until we expand one straight line.

Applications of Linear Pair of Angles

At the moment we have learned what linear pairs are and have observed some instances, let’s check how this theorem can be utilized in geometry and the real-life scenario.

In Real-Life Situations

There are many implementations of linear pairs of angles in real-world. One such case is architects, who apply these axioms in their daily job to check if two lines are perpendicular and creates a straight angle.

Construction and Building professionals also use masters in this field to make their work simpler. They use linear pairs of angles to assure that two close walls form a 90-degree angle with the floor.

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

In Geometry

Linear pairs of angles as well perform a role in geometry proofs. A regular proof that employs linear pairs is the alternate interior angles theorem. This theorem states that if two lines are parallel and intersected by a transversal line, the alternate interior angles created are congruent.

The proof of vertical angles additionally replies on linear pairs of angles. Even though the adjacent angles are supplementary and add up to 180 degrees, the opposite vertical angles are always equivalent to one another. Because of above-mentioned two rules, you only need to determine the measurement of one angle to work out the measurement of the rest.

The concept of linear pairs is also utilized for more complex uses, such as determining the angles in polygons. It’s important to grasp the fundamentals of linear pairs, so you are ready for more complex geometry.

As you can see, linear pairs of angles are a comparatively easy theorem with few engaging implementations. Later when you're out and about, observe if you can notice any linear pairs! And, if you're attending a geometry class, be on the lookout for how linear pairs might be useful in proofs.

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