Angles Everywhere

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SWBAT identify and create angle measures of supplementary and complementary angles

Big Idea

What is the difference between supplementary and complementary?


5 minutes
  • POD

As students enter the room, they will have a seat, take out their Problem of the Day (POD) sheet and begin to work on the question on the SMARTboard. The POD allows students to use MP 3 continually based on the discussions we have about the problem each day.

The POD will attempt to help students form a basis for separating the definitions of complementary and supplementary angles. In the past, students have decided that to “compliment” someone is to say they are cute. So the way they remember what complementary angles measure is to think of them as two “cute” angles (meaning they are less than 90o). I want to trigger this type of discussion so students develop ways to remember.

What is an easy way to remember the difference between complementary and supplementary angles?


30 minutes

The activity today will help students identify complementary and supplementary angles. Students will work with partners to identify the complementary and supplementary angles in each diagram or picture. Students will determine the measure of each angle that is not labeled with an angle measure. There are two cards included for students to draw their own diagrams. They can also draw a diagram on another sheet and glue it to the additional cards. After each pair has completed the activity, we will share the student-created cards using the document camera and find the missing angles in those pictures or diagrams. I want students to explain how they determined the missing angle measures with the rest of the class. If there are divergent strategies, it will be interesting to hear student explanations. How did students find the missing angles? Do they understand that supplementary angles combine to form a straight line? 


5 minutes

To wrap up class I want students to identify at least 3 real world examples of complementary and supplementary angles. I want them to make a connection between what they have learned and what they see everyday. This connection will make the learning more relevant and give them a resource to refer to to solidify their knowledge. If they can picture it in real life, outside of the classroom, they are more inclined to remember.