Ch 5: Angles & Triangles

About This Chapter

This chapter takes a close look at angles and triangles, with lessons on related measurements, properties, and terms. Your students will learn about these geometrical operations on both a fundamental and applicable level.

Angles & Triangles - Chapter Summary

This chapter is all about navigating angles and triangles in geometry. It aims to boost your students' understanding of relevant geometrical properties, forms of measurement, and mathematical applications. By the time your students finish going through these lessons, they'll be better prepared to apply knowledge of the following topics:

  • Measuring the angles of a polygon
  • Defining the interior and exterior angles of a triangle
  • Triangular medians, altitudes, and angle bisectors
  • Angles created by a transversal
  • Like triangles and the AA criterion
  • Solving problems with similar triangles
  • The transitive property

With every lesson containing both a video and transcript of the content, you'll be able to select the way you want your students to learn each topic. If you watch the videos, you and your students can skip around main points of the material by means of the timeline feature, while readers of the transcripts will find key terms highlighted in bold.

7 Lessons in Chapter 5: Angles & Triangles
Test your knowledge with a 30-question chapter practice test
How to Measure the Angles of a Polygon & Find the Sum

1. How to Measure the Angles of a Polygon & Find the Sum

Watch this video lesson to learn the one formula that lets you find the measure of angles in any regular polygon. Also, learn how you can tell if you are working with a regular polygon or not.

Interior and Exterior Angles of Triangles: Definition & Examples

2. Interior and Exterior Angles of Triangles: Definition & Examples

Knowing just a few things about the interior or exterior angles of triangles is sometimes all you need to put all the pieces together. Find out more in this lesson.

Median, Altitude, and Angle Bisectors of a Triangle

3. Median, Altitude, and Angle Bisectors of a Triangle

Line segments in triangles are just clutter; they have special names and qualities depending on how they're drawn. In this lesson, we'll learn about medians, altitudes and angle bisectors.

Angles Formed by a Transversal

4. Angles Formed by a Transversal

When you have a pair of parallel lines and a transversal, something very interesting happens to the angles that are formed. You can see this happen in real life at street intersections and such. Watch this video lesson to learn about all of this.

Similar Triangles & the AA Criterion

5. Similar Triangles & the AA Criterion

This video lesson explains the AA criterion and shows you why you only need two corresponding angles to be equal for two triangles to be similar. You will also see how you can use it to help you identify similar triangles.

Applications of Similar Triangles

6. Applications of Similar Triangles

Similar triangles are used to solve problems in everyday situations. Learn how to solve with similar triangles here, and then test your understanding with a quiz.

The Transitive Property of Similar Triangles

7. The Transitive Property of Similar Triangles

Watch this video lesson and you will understand what the transitive property is and how it applies to similar triangles. Watch as we apply the transitive property to three similar triangles.

Chapter Practice Exam
Test your knowledge of this chapter with a 30 question practice chapter exam.
Not Taken
Practice Final Exam
Test your knowledge of the entire course with a 50 question practice final exam.
Not Taken

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Support