Prove It with Angle Relationships

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SWBAT identify, describe and apply key angle relationships in proofs.

Big Idea

We will brainstorm and investigate how angles are related and apply these ideas to tricky application problems and proofs!

Do Now

10 minutes

Students can work independently to identify key geometric properties including reflexive property, symmetric property and transitive property.

Pair-Share for Angle Relationship Vocabulary

25 minutes

Practice with Scaffolded Proofs

15 minutes

Using student notes on page 6, students can cut out the key pieces of a practice proof.  Students can work in pairs or small groups to arrange the proof and then glue or paste the correct order of the proof onto page 8 of notes. You may want to consider how this proof could be created as a paragraph proof, rather than a 2-column proof before asking students to cut the pieces of the proof up (MP #7). 

Please note that page 7 has been left blank for students to cut out the pieces of their proof. 

You can review the steps with students, and discuss how these are connected to prior topics covered in geometry (i.e. sums of angles and reflexive property) (MP #3). 


10 minutes

Students will work on activity attached to student notes and continue this as a homework assignment, if time is short in class.

Review Video

8 minutes

You can start this video at minute 1.  Sir Tyler reviews the major angle relationships discussed in class.  He is funny, quarky and provides a great overview of today's lesson.

Exit Ticket

10 minutes

To determine if students have met the lesson objective, they are asked to write 2-3 statements about pairs of angles based on the diagram.