In geometry, an angle consists of two rays that share the same endpoint. The point where the rays intersect is called the vertex of the angle. The two rays are called the sides of the angle.
You can name an angle by specifying three points: two on the rays and one at the vertex.
The angle below may be specified as angle ABC or ∠ABC. The vertex point is always given in the middle.
The size of an angle is measured in degrees with the use of a protractor.
A straight line has an angle of 180°
The sum of angles around a point will always be 360 degrees.
In the diagram above, the sum of the angles is 70° + 55° + 50° + 65° + 120° = 360°
Example 1: Given the diagram below, determine the value of the angle a.
Solution:
Step 1: Get the sum of the known angles.
30° + 65° + 150° + 73° = 318°
Step 2: Subtract sum of known angles from 360°
360° 318° = 42°
Answer: Angle a is 42°
Worksheets for Angles Around a Point
What are angles around a point?Try the free Mathway calculator and
problem solver below to practice various math topics. Try the given examples, or type in your own
problem and check your answer with the step-by-step explanations.
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.