About This Chapter
How it works:
- Identify the lessons in the McDougal Littell Geometry Textbook Perpendicular and Parallel Lines chapter with which you need help.
- Find the corresponding video lessons within this companion course chapter.
- Watch fun videos that cover the perpendicular and parallel lines 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:
- Defining and applying direct proofs
- Comparing types of proof
- Constructing perpendicular lines in geometry
- Proving results about perpendicular lines
- Theorems about parallel lines
- Theorems about transversals
- Parallel line proofs
- Using converse statements to prove lines are parallel
- Constructing a parallel line using a point not on the given line
- The parallel postulate and indirect proof
- Identifying the different parts of a graph
- The Cartesian coordinate system
- Calculating the slope of a line
- Using coordinates to prove geometric theorems
- Proving the slope criteria
- Solving geometric problems using the slope criteria
McDougal Littell Geometry is a registered trademark of McDougal Littell, which is not affiliated with Study.com.
1. Parallel, Perpendicular and Transverse Lines
What are the different types of lines? Where are they visible in the real world and how can you recognize them? Find out here and test your knowledge with a quiz.
2. 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.
3. Direct Proofs: Definition and Applications
In math, we can't explain that something is true just because. That's not enough. In this lesson, we'll learn to prove things using one of our most straightforward tools, the direct proof.
4. Constructing Perpendicular Lines in Geometry
In this video lesson, you will see how to use geometric construction to draw perpendicular lines. Learn why geometric construction is useful. Also find out the only two tools in addition to your pencil that you need to do this.
5. Parallel Lines: How to Prove Lines Are Parallel
Watch this video lesson to learn how you can prove that two lines are parallel just by matching up pairs of angles. Learn which angles to pair up and what to look for.
6. Using Converse Statements to Prove Lines Are Parallel
Because a pair of parallel lines produces unique angle characteristics, we can use this information to our advantage. Watch this video lesson to see how we turn this advantage into converse statements to help us prove parallel lines.
7. Constructing a Parallel Line Using a Point Not on the Given Line
Watch this video lesson, and you will learn how to draw parallel lines with just a compass and a straightedge. Also, learn why you would want to be able to do this in real life.
8. The Parallel Postulate: Definition & Examples
In this lesson, you will learn about an important postulate in Euclidean geometry, called the Parallel Postulate. It sounds kind of hard, but this lesson explains it in simple terms and provides several examples of it as well.
9. What Are the Different Parts of a Graph?
Being able to read a graph isn't just vital for an algebra class. Graphs and charts are used everywhere! We'll take a crash course on the basic x/y plane used in algebra and the fundamental vocab you need.
10. The Cartesian Coordinate System: Plotting Points & Graphing Lines
Watch this video lesson to see how useful the Cartesian coordinate system is. Learn how points are labeled and how you can plot points and graph lines using the system.
11. Calculating the Slope of a Line: Point-Slope Form, Slope-Intercept Form & More
Being able to calculate the slope of a line is a very useful skill to have. Why? Watch this video lesson to find out and learn how to find the slope when working with various equations and various lines.
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.
Other chapters within the McDougal Littell Geometry: Online Textbook Help course
- McDougal Littell Geometry Chapter 1: Basics of Geometry
- McDougal Littell Geometry Chapter 2: Reasoning and Proof
- McDougal Littell Geometry Chapter 4: Congruent Triangles
- McDougal Littell Geometry Chapter 5: Properties of Triangles
- McDougal Littell Geometry Chapter 6: Quadrilaterals
- McDougal Littell Geometry Chapter 7: Transformations
- McDougal Littell Geometry Chapter 8: Similarity
- McDougal Littell Geometry Chapter 9: Right Triangles and Trigonometry
- McDougal Littell Geometry Chapter 10: Circles
- McDougal Littell Geometry Chapter 11: Area of Polygons and Circles
- McDougal Littell Geometry Chapter 12: Surface Area and Volume