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Module 7

1. Module 7

1.11. Lesson 3

Mathematics 10-3 Module 7 Lesson 3

Module 7: Trigonometry

 

Lesson 3: The Sine Ratio

 

Focus

 

This is a photograph of Sandra Post, a renowned Canadian golfer.

© 2010 Sandra Post. Reproduced with permission.

Sandra Post, who was born in 1948 in Oakville, Ontario, is Canada’s most successful female golfer. She won her first Ladies’ Professional Golf Association (LPGA) championship at the age of 20, and Post was the youngest golfer to win an LPGA major title. This record held up until 2007. Before her retirement from the LPGA Tour in 1984, she won eight major championships, and she was a runner-up twenty times!

 

For the avid golfer, the game is a challenge. Not even the best golfers in the world always hit their shots on the fairway. Regardless of how often the player practises at the driving range, during the actual game the ball seems to have a mind of its own. Instead of going straight down the fairway, the ball will hook or slice wildly, travelling at a wicked angle to the desired path, and end up in the rough or bush, or nestled at the bottom of a sand trap.

 

Even a small angle off course can result in trouble. Suppose your average drive is 250 yd. If the ball ends up 5° off course, how many yards will it end up off the desired path? Surely it can’t be too far! After all, 5° is a small angle, isn’t it?

 

To answer this question, you will need to apply trigonometry and a new ratio called the sine function.

 

Lesson Questions

 

In this lesson you will explore these questions:

  • What is the sine ratio?

  • How is the sine ratio used to find unknown sides and angles in right triangles?

Assessment

 

You will complete the Lesson 3 Assignment Booklet for assessment. Download the Lesson 3 Assignment Booklet and save it in your course folder now. You will receive instructions on how to complete the Assignment Booklet later in the lesson. You will also be prompted to start working on the Unit 3 Assessment.

 

Remember to save all activities, including those that are not part of the Assignment, in your course folder.

 

Required Materials and Equipment

 

You will need your clinometer, a tape measure, a metric ruler, your protractor, and a calculator.