Math 20-2

Chapter 3 Acute Triangle Trigonometry

Lesson 3.4 Solving Problems Using Acute Triangles

GOAL

The goal of this lesson is stated at the top of page 154 in your textbook, and is also written below.
Keep this in mind as you work through the lesson material.

Solve problems using the primary trigonometric ratios and the sine and cosine laws.

Explore...

Try to answer the question in the sidebar on page 154.

This “explore” asks YOU to make up your own question involving the cosine law.
If you do, excellent!
Share it with another student or your teacher.

I could make up my own question for you to do, but you’ll get plenty of practice working through the provided problems for the lesson.

Learn About the Math

Information and Examples that present the ideas of this lesson

TEXT Pages 154 - 156

Read/Work through the Learn About the Math section on Pages 154-156 in your textbook.

Go through this material,  AS BEST YOU CAN,  before you view the video tutorials that follow.

Example 1    Connecting an acute triangle model to a situation

Video Tutorial     (Vlad's solution)
Using primary trigonometric ratios and the cosine law

If you watch the video for Vlad’s solution, that should hopefully provide enough help to be able to follow Michel’s solution.

Apply the Math  (Examples)

Examples will give you TOOLS for solving problems, and also show you that there may be different ways to approach a question.

YOUR TURN gives YOU the chance to try to do a problem ON YOUR OWN,  using the examples as models.

Example 2  Connecting acute triangle models to indirect measurement

TEXT Pages 157 - 158

Work through Example 2 on Pages 157 - 158 in your textbook.

Watch

Video Tutorial

Your Turn

I answered this when I did the video for the example

Example 3  Solving a three-dimensional problem

TEXT Pages 159 - 160

Work through Example 3 on Pages 159 - 160 in your textbook.

Watch

Video Tutorial

Your Turn

You were asked to make up your own question here,  so I didn’t do a video for this one.

In Summary

Key Ideas and Need to Know 
Presents and summarizes  the main new concepts of the lesson

•	Carefully read through each of the bullet points in this section.

•	If you are unclear about any of these ideas,  ASK YOUR TEACHER FOR HELP!

Practice Problems

Doing Practice Problems

Practice problems reinforce the math presented in this lesson.

•	Work through the practice problems for this lesson.
	These problems are for practice, you don’t need to hand them in!
	(your teacher may assign specific questions for you to complete)

•	Use the answers in the back of the book to CHECK YOUR WORK!

•	If you make a mistake, TRY TO FIX IT!

•	If you need help or want more information, view the video solutions provided.

•	If you still need more help,  CONTACT YOUR TEACHER!

Types of Practice Problems

Check Your Understanding questions require basic understanding of the ideas of the  lesson.

Practising questions will require you to dig deeper for a solution.

Closing  A summary question that often asks YOU to explain ideas in your own words.

Extending questions offer enrichment and extension.

Notes

Question 15,    I didn’t do a video for this one.

Video Solution Links

Check your work for every problem you do!
If you make a mistake,  try to fix it!
Use the video solutions for more information.
If a problem still doesn’t make sense, ASK YOUR TEACHER FOR HELP!

({{"Question 1", "Question 2", "Question 3", "Question 4", "Question 5"}, {"Question 6", "Question 7", "Question 8", "Question 9", "Question 10"}, {"Question 11", "Question 12", "Question 13", "Question 14",  }, {"Question 16", "Question 17", , , }})