Title
Skill
Angle Sum, Exterior Angle Theorem, Supplement Theorem
Using Text as Evidence to Support an Argument
EBA Activity Using Evidence Four Corners
Claim

It is easier to find a missing angle measure by using the Angle Sum
Theorem rather than the Exterior Angle Theorem.

The better way to find the missing angle measures below is Method 1.
105°
Y Y X
Method 1 Method 2
Procedure
Timing/Pacing
Notes
Use angle sum followed by the supplement theorem
Use angle sum then exterior angle theorem
1.
Students will solve for a missing angle measure by using the Angle
Sum Theorem as well as the Exterior Angle Theorem using text from the textbook.
2.
Students will be asked to find the missing angle measure using both
Method 1 and Method 2.
3.
Continue with standard Using Evidence Four Corners activity.

Before this lesson student will have learned how to identify and classify triangles by sides and angles. Students will be able to find measures of the unknown sides of triangles. After this lesson student will be able to name and label corresponding parts of congruent triangles and identify congruence transformations.

This activity will take 20 minutes.

This activity will be at the end of the lesson. Before this activity student will have learned the definition of and how to apply the Angle Sum and
Exterior Angle Theorem. After this activity students can write a reflection on the Four Corners activity and work independently on practice problems.
This debate shows students there is more than one approach to solving geometric problems. By solving both types of problems before the debate, and working in groups to come up warrants to support their claims, students are able to deepen their understanding of the two approaches concepts and reflect after the debate. A listening and speaking rubric can also be used as an assessment tool for this activity.
Boston Debate League © 2012

Follow Up
Activities
Text
To add a writing component, follow up with a Mini Paragraph Writing
Exercise.
Standard Geometry Text
Boston Debate League © 2012

Name:_____________________________________ Class: __________ Date:______________
Four Corners
Background Information
105°
Y Y X
Method 1 Method 2
Use angle sum followed by the supplement theorem
Use angle sum then exterior angle theorem
Claim
It is easier to find a missing angle measure by using the
Angle Sum Theorem rather than the Exterior Angle
Theorem.
Strongly Agree Disagree Strongly
Agree Disagree
The better way to find the missing angle measures above is Method 1.
Strongly Agree Disagree Strongly
Agree Disagree
Speech Structure
Text (with page or line)
“I _________________ with the claim
Analysis
______________________________________________________________________.
My warrant for this stance is from ________________________________, which states
______________________________________________________________________.
This supports my stance because
_____________________________________________________________________.”
Boston Debate League © 2012