Big ideas math geometry chapter 9 answer key

About This Chapter

The Right Triangles and Trigonometry chapter of this Big Ideas Math Geometry Companion Course aligns with the same chapter in the Big Ideas Math Geometry textbook. These simple and fun video lessons are about five minutes long and help you learn the essential lessons about the Pythagorean Theorem, types of right triangles and basic trigonometry.

How It Works:

• Find the lesson within this chapter that corresponds to what you're studying in the Right Triangles and Trigonometry chapter of your textbook.
• Watch fun videos that cover the triangle and trigonometry concepts you need to learn or review.
• Complete the quiz after watching each video lesson 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.

Chapter Topics

You'll learn all of the geometry topics covered in the textbook chapter, including:

• Applying the Pythagorean Theorem
• What the types of special right triangles are
• Trigonometric ratios and functions
• The law of sines and the law of cosines

Big Ideas Math is a registered trademark of Larson Texts, Inc., which is not affiliated with Study.com.

Test your knowledge with a 30-question chapter practice test

1. Pythagorean Theorem: Definition & Example

Pythagorean theorem, named after the mathematician Pythagoras, shows the relation between the sum of the squares of each of the three sides of a right triangle. Learn about the definition of the Pythagorean theorem, discover how a right triangle and sides of a triangle are used in the equation of the theorem, and explore the application of the Pythagorean theorem through relevant examples.

2. The Pythagorean Theorem: Practice and Application

Discover how the Pythagorean theorem helps people to solve for all sides of a triangle. Learn about the basics, purpose, and applications of the Pythagorean theorem.

3. The Pythagorean Theorem: Converse and Special Cases

The Pythagorean Theorem states that the square of the hypotenuse of a right triangle will always equal the sum of the squares of the two sides. Learn about the law of cosines, special cases, and the converse of the Pythagorean Theorem.

4. Special Right Triangles: Types and Properties

There are two types of special right triangles that have either 30-60-90 degree angles or 45-45-90 degree angles. Learn more about the definitions and explore the properties of 30-60-90 and 45-45-90 degree angles of special right triangles through examples.

5. Trigonometric Ratios and Similarity

In mathematics, trigonometric ratios explore the measurements of the angles and sides of right triangles. Learn about trigonometric ratios and similarities as they apply to right triangles, what causes two right triangles to be similar, and how to calculate sine, cosine, and tangent.

6. Practice Finding the Trigonometric Ratios

Trigonometric ratios can help determine the lengths of the sides of a triangle in different situations. Learn what trigonometric ratios are, learn how to solve for sides and angles, and practice finding these trigonometric ratios in a practice problem.

7. Properties of Inverse Trigonometric Functions

Inverse trigonometric functions are the inverse of the usual sine, cosine, and tangent functions, and they can be written two ways. Learn more about inverse trigonometric functions, including their notation, limited range, and how they appear on a graph.

8. Law of Sines: Definition and Application

Law of Sines, also known as sine law or sine rule, is an equation relating the sines of the three angles of a triangle to its three sides. Learn about the definition of the Law of Sines and understand how to apply it by completing math problems involving triangles.

9. Using the Law of Sines to Solve a Triangle

The law of sines is useful in solving a triangle since it makes use of the relationships of the sides and angles of a triangle. Learn how to solve triangles using the law of sines through the given examples.

10. Law of Cosines: Definition and Application

The law of cosines is an equation that considers the two known sides of a triangle and the cosine of one of its known angles to find the one missing side. Explore the definition and application of the law of cosines and learn how to solve problems involving triangles through the given practice problems.

11. Solving Real World Problems Using the Law of Cosines

Discover how the law of cosines is used by surveyors and others to solve problems in the real world. Review the law of cosines, explore real world uses, and look closer at two examples to better understand its real-world application.

Test your knowledge of this chapter with a 30 question practice chapter exam.

Test your knowledge of the entire course with a 50 question practice final exam.

There are even more practice exams available in Big Ideas Math Geometry Chapter 9: Right Triangles and Trigonometry.

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