Proof Writing in High School Geometry (Two-Column Proofs) - Introduction:
This full unit pack (108 pages including answer keys) has all the resources you need to teach your Geometry students how to write proofs. It begins at the most basic level with the properties and postulates that will later become justifications in their proofs.
The unit teaches the structure and process for writing a proof, beginning with basic algebra proofs. Students get comfortable with substitution and the transitive property before being led into Geometry proofs.
A full presentation in color is included as well as a set of black and white printables with practice, differentiated warm-ups, quizzes, a graphic organizer, blank proof templates, and a puzzle activity. There are plenty of worksheets containing proofs in a variety of difficulty levels. All answer keys are included. A pacing guide is also included.
The presentation pages walk the students through step-by-step and include hints and tips. Please see the preview for more information and sample pages.
The zip file includes a presentation and a set of printables (PDF).
Topics included (justifications used in proofs):
Addition Property of Equality
Subtraction Property of Equality
Multiplication Property of Equality
Division Property of Equality
Reflexive Property (of Equality and Congruence)
Symmetric Property (of Equality and Congruence)
Transitive Property (of Equality and Congruence)
Substitution Property (of Equality and Congruence)
Segment Addition Postulate
Angle Addition Postulate
Definition of Congruence
Definition of Midpoint
Definition of Bisector
Definition of Right Angle
Definition of Perpendicular
Vertical Angles Theorem
Right Angles Theorem
Linear Pair Theorem
Corresponding Angles Postulate
Alternate Interior Angles Theorem (and its Converse)
Alternate Exterior Angles Theorem (and its Converse)
Same-Side Interior Angles Theorem (and its Converse)
Same-Side Exterior Angles Theorem (and its Converse)
Triangle Sum Theorem
Base Angles of Isosceles Triangles Theorem (and its Converse)
This unit goes up to, but does not include congruent triangles.
If students are not already familiar with special angle pairs (complementary, supplementary, vertical angles, etc, you may be interested in this supplementary resource as well:
If students are not already familiar with transversals, you may be interested in this supplementary resource as well:
You may also like these other Geometry Resources: