Adjacent Angles

Adjacent angles are two angles that share a common vertex and a common side. The non-common sides of the angles form a straight line. In other words, adjacent angles are angles that are next to each other and share a common side.

Key Points:

• Adjacent angles share a common vertex and a common side.
• The non-common sides of adjacent angles form a straight line.
• Adjacent angles do not overlap.

Examples:

Here are a few examples of adjacent angles:

• Example 1: In the figure below, angle AOC and angle COB are adjacent angles.
Angles Example 1">
• Example 2: In the figure below, angle 1 and angle 2 are adjacent angles.
Angles Example 2">

Properties:

There are a few important properties of adjacent angles:

• The sum of the measures of adjacent angles is always 180 degrees, because the non-common sides form a straight line.
• If two adjacent angles form a right angle (90 degrees), then they are complementary angles.

Study Guide:

Here are some key points to remember about adjacent angles:

• Adjacent angles share a common vertex and a common side.
• The non-common sides of adjacent angles form a straight line.
• The sum of the measures of adjacent angles is always 180 degrees.
• If two adjacent angles form a right angle, then they are complementary angles.

Now that you understand adjacent angles, you can practice identifying them in different geometric figures and solving problems involving their measures.