Angles By: Emily Angleberger

Vertex Each angle has a vertex. Each angle has a vertex. A vertex is the point where two rays meet and form an angle A vertex is the point where two rays meet and form an angle Vertex Ray 1 Ray 2

Naming Angles A B C ABC CBA B You can name an angle by all three points, with the vertex in the center. Or you can use just the letter of the vertex.

Let’s Name These Angles Write the name of these angles in three different ways. Write the name of these angles in three different ways. A B C E D F H G I J K L EFD DFE F JLK KLJ L ABC CBA B HIG GIH I

Classifying Angles An acute angle measures less than 90°. A right angle measures exactly 90°. An obtuse angle measures more than 90°.

Classify These Angles Acute, Obtuse, or Right Obtuse Acute Acute Right

Let’s Measure Angles! eb/mentalmaths/protractor.html eb/mentalmaths/protractor.html eb/mentalmaths/protractor.html eb/mentalmaths/protractor.html