1. Module 5

1.16. Lesson 4

Mathematics 10-3 Module 5 Lesson 4

Module 5: Angles

 

Lesson 4: Relationships Among Angles

 

Focus

 

This photograph is of shadows made by the goal posts on a soccer pitch.

© Tina Rencelj/shutterstock

Did You Know?

 

Soccer is the most-watched sport in the world. Soccer is called football outside of North America.


 

This illustration shows a soccer goal sitting in its place on the pitch. The angle between the side of the goal and the goal line is highlighted in blue. The shadow of the goal post divides the blue angle into two parts. The shadow is highlighted in red.

© Tina Rencelj/shutterstock

Geometry is the study of shapes and their relationships. The search for relationships is important in all branches of mathematics. In fact, seeking patterns and relationships is a strong function of the human mind! Art, architecture, games, and music all make use of patterns.

 

Shapes, patterns, and relationships are all around you. For example, look at the interplay between the light and shadows by the goal on the pictured soccer pitch. You will see triangles, trapezoids, parallelograms, and a variety of angles. You will even see patterns on the grass!

 

The shadow of the goalpost nearest you divides a right angle into two acute angles, as you can see in the second image. What terms describe this angle pair?

 

Lesson Questions

 

In this lesson you will explore these questions:

  • What are complementary and supplementary angles?
  • What are vertically opposite angles?
  • How are complementary and supplementary angles used to solve problems?
Assessment

 

You will complete the Lesson 4 Assignment Booklet for assessment. Download the Lesson 4 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 Project.

 

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

 

Required Materials and Equipment

 

For this lesson you will need the following supplies:

  • a protractor
  • tape
  • scissors
  • several blank sheets of paper
  • a straightedge or ruler