<meta http-equiv="refresh" content="1; url=/nojavascript/">
Skip Navigation

Linear Pairs

Two adjacent angles that form a straight line.

Atoms Practice
Practice Linear Pairs
Practice Now
Linear Pairs

What if you notice two angles in a picture that make a straight line? What information does this give you about the angles? After completing this Concept, you'll be able to apply the properties of linear pairs to help you solve problems.

Watch This

CK-12 Foundation: Chapter1Linear PairsA

James Sousa: Linear Pairs


Adjacent angles are two angles that have the same vertex, share a side, and do not overlap. In the picture below, PSQ and QSR are adjacent.

A linear pair is two angles that are adjacent and whose non-common sides form a straight line. If two angles are a linear pair, then they are supplementary.

PSQ and QSR are a linear pair.


Example A

What is the value of each angle?

These two angles are a linear pair, so they are supplementary, or add up to 180. Write an equation.


So, plug in q to get the measure of each angle.


Example B

Are CDA and DAB a linear pair? Are they supplementary?

The two angles are not a linear pair because they do not have the same vertex. However, they are supplementary, 120+60=180.

Example C

Name one linear pair in the diagram below.

One example is INM and MNL.

Watch this video for help with the Examples above.

CK-12 Foundation: Chapter1LinearPairsB

Guided Practice

1. What is mINL?

2. What is mLNK?

3. If mINJ=63, find mMNI.


1. 180

2. 90

3. 18063=117

Interactive Practice

Explore More

For 1-5, determine if the statement is true or false.

  1. Linear pairs are congruent.
  2. Adjacent angles share a vertex.
  3. Adjacent angles overlap.
  4. Linear pairs are supplementary.
  5. Supplementary angles form linear pairs.

Find the measure of an angle that forms a linear pair with MRS if mMRS is:

  1. 54
  2. 32
  3. 104
  4. 71
  5. 149
  6. x

For 12-16, find the value of x.


Adjacent Angles

Adjacent Angles

Two angles are adjacent if they share a side and vertex. The word 'adjacent' means 'beside' or 'next-to'.


A diagram is a drawing used to represent a mathematical problem.
linear pair

linear pair

Two angles form a linear pair if they are supplementary and adjacent.

Image Attributions


Please wait...
Please wait...

Original text