Angles
Overview
Expect to see questions that test your understanding of angles and their properties. In this section we’ll cover the following:
 Angle Basics
 Classifying Angles by Size
 Classifying Angles Relationships
 Identifying Angle Properties in Other Geometric Figures
Let’s look at each of these in more detail:
Angle Basics
What is an angle? Look at this definition.
To review angle basics, click on this link. It is a presentation that goes over this topic.
Classifying Angles by Size
Angles range from 0° to 360°. Depending on the measure of the angle, it can fall into several categories of angles.
 An angle whose measure is less than 90° is an acute angle.
 An angle greater than 90° and less than 180° is an obtuse angle.
 An angle that measures 90° is a right angle.
 An angle greater than 180° and less than 360° is called a reflex angle.
 An angle that is 180° is called a straight angle.
To learn more about classifying triangles by angle measures, click on this link. It is a presentation that goes over this topic.
Classifying Angles Relationships
Angles can be classified by their angle measure. Often angles are associated with other angles. For example, two angles can share a side:
Angles make up the interior of polygons:
Or, when two lines intersect, four angles are formed:
Take a look at this link to see a presentation on these different angle relationships. In particular, make sure you understand the following types of angle relationships:
 Complementary Angles
 Supplementary Angles
 Vertical Angles
A special case of angle relationships happens when two parallel lines are cut by a transversal.
Click on this link to see a presentation that shows all the angles formed by this configuration. Make a note of the congruent and supplementary angles formed.

Identifying Angle Properties in Other Geometric Figures
Make sure you are familiar with key triangle theorems that relate to angle measures. They will often be part of solving a particular SAT problem involving triangles.
Click on this link to see a slide show of these theorems.

About Media4Math
All of the resources in this overview can be found on Media4Math. Subscribers can download these resources, or create their own slide shows using Slide Show Creator.