Proof Writing in High School Geometry (Two-Column Proofs):
This versatile set of 12 geometry proof problems can be used in many ways.
You get the set of 12 proof problems in two formats : one with a two-column table set up for recording, and one without. A student recording sheet is included as well. Answer keys are included, but there may be other possible approaches to some proofs.
Option 1: Print one set of task cards and laminate them. Print a “recording sheet” for each student. They can work in small teams or rotate through stations to complete tasks.
Option 2: Print multiple cards per page to create worksheets for student practice.
Option 3: One proof at a time can be projected for full-class practice.
Option 4: Use an assortment of proofs to create an assessment.
Concepts Used in Justifications for Proofs in this set (prior knowledge required):
Angle Addition Postulate
Segment Addition Postulate
Corresponding angles Postulate
Alternate interior angles Theorem
Alternate exterior angles Theorem
Same-side interior angles Theorem
Same-side exterior angles Theorem
“Right angles are congruent”
“Base angles of Isosceles triangles are congruent”
(+ converses of any of the above where applicable)
See preview for views of the two formats of task cards and some samples. The zip file contains PDF files.
Check out a full unit - teaching proofs from the very beginning:
Proofs: Full Unit
For more task cards, try:
Algebra In Geometry Task Cards: Finding Missing Angle Measures
Task Cards: Slopes of Parallel and Perpendicular Lines
For more great high school Geometry resources, try:
Lesson Pack: Transversals