1. Module 7

1.29. Lesson 6

Mathematics 10-3 Module 7 Lesson 6

Module 7: Lesson 6

 

Lesson 6: Using Cosines to Solve Problems

 

Focus

 

In this photo, skip Cheryl Bernard yells for her sweepers to sweep a rock.

Alex Livesey/Getty Images Sport/Getty Images

 

In the photograph, skip Cheryl Bernard of Calgary is calling out instructions to her sweepers. Skip Bernard and her rink won the silver medal in women’s curling at the 2010 Winter Olympics in Vancouver.

 

Curling can be a game of inches. The difference between winning and losing can depend on the sweepers’ ability to determine at what pressure and speed to sweep the rock. Success can also depend on how accurate the curler was when she released the stone.

 

From the point where a curler must release her rock to the centre of the rings at the other end of the rink is 93 ft. Suppose the skip positions her broom along the T-line in the house at 2.5° to the right of the centre line, as seen from the curler who is throwing the stone.

 

 

This illustration shows a sheet of ice for curling. Overlaying the sheet is a right triangle with vertex A at the point where a curler releases her rock. The side adjacent to angle A extends 93 feet along the centre line to the T-line at the other end of the rink. The side opposite angle A is a line segment on the T-line that runs from the centre line to the skip’s broom position. The skip’s broom is positioned on the T-line so that it is 2.5 degrees to the right of the centre line as seen from the curler who is throwing the stone from point A.

 

How far is the broom, to the nearest inch, away from the point where the curler must release the stone?

 

Lesson Questions

 

In this lesson you will explore this question:

  • How is the cosine ratio used to solve a variety of practical problems?

Assessment

 

You will complete the Lesson 6 Assignment Booklet for assessment. Download the Lesson 6 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.

 

Remember to save all of your work in your course folder.

 

Required Materials and Equipment

 

You will need your tape measure and your calculator.