# Ch 4: McDougal Littell Geometry Chapter 4: Congruent Triangles

The Congruent Triangles chapter of this McDougal Littell Geometry: Online Textbook Help course helps students learn essential geometry lessons of congruent triangles. Each of these simple and fun video lessons is about five minutes long and is sequenced to align with the Congruent Triangles textbook chapter.

## How it works:

• Identify the lessons in the McDougal Littell Geometry's Congruent Triangles chapter with which you need help.
• Find the corresponding video lessons within this companion course chapter.
• Watch fun videos that cover the congruent triangles topics you need to learn or review.
• Complete the quizzes to test your understanding.
• If you need additional help, rewatch the videos until you've mastered the material or submit a question for one of our instructors.

## Students will learn:

• The definition and properties of triangles
• Classification of triangles by angles and sides
• Interior and exterior angles of triangles
• Angles of triangle measurement
• Identification of congruent figures and corresponding parts
• Congruence proofs
• Converse of a statement
• Similarity transformations in corresponding figures
• Triangle congruence postulates
• Relationships proofs in figures using congruence and similarity
• The AAS (angle-angle-side) theorem
• Properties of concurrent lines in a triangle
• Use of congruent triangles to prove constructions are valid
• The HA (hypotenuse angle) theorem
• The HL (hypotenuse leg) theorem
• Base angles theorem and converse of the base triangles theorem
• Congruency of isosceles triangles
• Right triangles congruency
• Congruency of equilateral triangles
• Placement of figures in a coordinate plane
• Use of the midpoint formula
• Application of congruent triangles to plan and write proofs

McDougal Littell Geometry is a registered trademark of Houghton Mifflin Harcourt, which is not affiliated with Study.com.

14 Lessons in Chapter 4: McDougal Littell Geometry Chapter 4: Congruent Triangles
Test your knowledge with a 30-question chapter practice test
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

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