# Ch 14: High School Geometry: Introduction to Trigonometry

Watch geometry video lessons and learn about trigonometric ratios, sines, cosines, tangents and more. Take the quizzes that follow each lesson to test your knowledge of trigonometry.

## Introduction to Trigonometry - Chapter Summary and Learning Objectives

Also known as 'trig,' this branch of math grew from geometry and is used in astronomy, navigation and surveying. In this chapter, you can extend your geometric knowledge and make further use of the Pythagorean Theorem to find distances and solve right triangles. You can also learn the laws of sines and cosines in addition to practicing their applications. This chapter is designed to teach you:

• Strategies for visualizing geometry problems
• Calculations for the volumes of basic shapes
• Use of the Pythagorean Theorem for finding distance
• Sines, cosines and tangents
• Similarity and trigonometric ratios
• How to solve right triangles
• How to find area
• Applications for the Laws of Sines and Cosines

Video Objective
How to Solve Visualizing Geometry Problems Apply a graphical and hands-on approach to visualizing geometry problems.
How to Calculate the Volumes of Basic Shapes Calculate the volume of spheres, pyramids and other basic shapes.
Finding Distance with the Pythagorean Theorem Apply the Pythagorean Theorem to find distance between points.
Trigonometry: Sine and Cosine Graph sines and cosines; describe them on right triangles.
Trigonometry and the Pythagorean Theorem Use trigonometry in conjunction with the Pythagorean Theorem.
Introduction to Sines, Cosines and Tangents Learn about the basic trigonometric ratios.
Trigonometric Ratios and Similarity Understand that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.
Practice Finding the Trigonometric Ratios Apply what you've learned to find trigonometric ratios in practice problems.
Sine and Cosine of Complementary Angles Explain and use the relationship between the sine and cosine of complementary angles.
The Pythagorean Theorem: Practice and Application Use trigonometric ratios and the Pythagorean Theorem to solve right triangles in applied problems.
Solving Right Triangles Use trigonometric ratios and the Pythagorean Theorem to solve right triangles in applied problems.
Problems Requiring Solving Right Triangles Use trigonometric ratios and the Pythagorean Theorem to solve right triangles in applied problems.
Using A = ½ ab sin (C) to Find Area Derive the formula A = ½ ab sin (C) for the area of a triangle by drawing an auxiliary line from a vertex perpendicular to the opposite side.
The Law of the Sines Prove the Laws of Sines and Cosines and use them to solve problems.
The Law of the Cosines Prove the Laws of Sines and Cosines and use them to solve problems.
Practice Applying the Law of the Sines and the Law of the Cosines Understand and apply the Laws of Sines and Cosines to find unknown measurements in right and non-right triangles (e.g., surveying problems, resultant forces).

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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