Lesson 7: Introduction to Trigonometry

Module 1 Part 2: Trigonometry

 

Lesson 7: Introduction to Trigonometry

 ** Always have your calculator in degree mode. Check by hitting the MODE button and looking at the third line. The word degree must be darkened**

Focus

 

treehouse: © Ewan Chesser/shutterstock; surveyor: © Joe Gough/shutterstock

 

As you have worked through the previous lessons, you have been adding shapes to create your own personal place. You have been asked to provide measurements and calculations for your shapes. Using a program like Google SketchUp makes it pretty easy to show measurements, since you can simply click on the tape measure and then drag the measure alongside your shapes. If only life were that simple!

 

Imagine building a tree house. There would be some measurements that are difficult to take, like the height of the tree—it’s not too easy (or safe) to climb a tree with a tape measure in your hands!

Luckily, there is a great mathematical concept called trigonometry. In the construction industry, surveying allows people to use trigonometry to calculate unknown lengths, so direct measurements are not required.

 

In this lesson you will explore trigonometry and answer questions such as, what does trigonometry mean and how does it work?

 

When you have completed this lesson, you will move on to Lesson 8 where you will learn how to solve for a missing side and then Lesson 9 where you will solve for a missing angle.

 

Outcomes

 

At the end of this lesson, you will be able to

• explain the meaning of sin, cos and tan in a right triangle.
• use the SIN, COS and TAN buttons on your calculator.

Lesson Questions

 

By the end of this lesson, you should feel comfortable solving the following questions:

• In what situations can the concepts of trigonometry be used to solve problems?

• How do I determine the sine, cosine, and tangent ratios for a given angle in a triangle?

• How do I use my calculator to find, sin, cos and tan for a given angle?

Lesson Completion and Assessment

 

As you work through each lesson, complete all the questions and learning activities in your binder using paper and pencil, clearly labeling your work (they refer to this as your course folder). These include the Are you Ready, Try This, Share and Self Check questions. Check your work if answers are provided. Remember that these questions provide you with the practice and feedback that you need to successfully complete this course.
Once you have completed all of the learning activities, take the Lesson Quiz. This is the assessment for each lesson and is locate under the Assess tab or by using the Quizzes link under the Activities block.

** Note – Share questions may have to be done on your own depending on your learning situation**

Mathematics 10C Learn EveryWare © 2010 Alberta Education