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Trigonometry For Dummies, 3rd Edition
book

Trigonometry For Dummies, 3rd Edition

by Mary Jane Sterling
March 2023
Beginner content levelBeginner
400 pages
9h 38m
English
For Dummies
Content preview from Trigonometry For Dummies, 3rd Edition

Chapter 17

Obeying the Laws and Applying Them

IN THIS CHAPTER

Bullet Finding missing parts in triangles

Bullet Understanding the laws of sines and cosines

Bullet Computing the areas of triangles

Triangles are very useful figures. Since humankind figured out how to keep records, people have documented the applications of triangles in mathematics and many other sciences and the arts. The right triangle gets the most use; Pythagoras saw to it that others recognized right triangles for the powerful polygons that they are. But oblique triangles (those that aren’t acute triangles or right triangles) have their place, too. You can’t always arrange to have a nice right triangle when you want it. Here’s where oblique triangles and the laws of sines and cosines come into play.

The law of sines uses — believe it or not — the sines of a triangle’s angles. With three carefully selected parts of the triangle (there are six to choose from), you can solve for the sizes of all the other parts. Of course, you have to obey the law, and the choices you can make are limited. That’s where the law of cosines comes in to save the day. This law isn’t as user-friendly, but it picks up where the law of sines falls short.

Trigonometry ...

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Publisher Resources

ISBN: 9781394168552Purchase Link