**Definition of Linear Pair**

- Linear Pair is a pair of adjacent angles that form a straight line.

**More About Linear Pair**

- The sum of the measure of the angles in a linear pair is supplementary or 180°.
- If one angle of a linear pair is acute (below 90o), then the other angle is obtuse (above 90o).

**Example of Linear Pair**

- In the above figure, ∠1 and ∠2, ∠2 and ∠3, ∠3 and ∠4, and ∠4 and ∠1 are linear pairs, as any pair of these angles forms a straight line.

**Solved Example on Linear Pair**

If

m∠CAB = 32, then find them∠CAD in the figure shown.

Choices:

A. 148

B. 212

C. 158

D. 32

Correct Answer: A

Solution:

Step 1:If ∠DAB is a straight angle, thenm∠CAD +m∠CAB = 180 [Angle Addition Postulate.]

Step 2:m∠CAD + 32° = 180° [Substitute.]

Step 3:m∠CAD = 148 [Simplify.]

**Related Terms for Linear Pair**

- Acute Angle
- Angle
- Adjacent Angles
- Line
- Obtuse Angle
- Pair
- Straight Line
- Supplementary Angles