Proof Writing in High School Geometry (Two-Column Proofs) - Introduction: This proof unit is a favorite with thousands of Geometry teachers, because unlike all the textbooks, it includes my unique transitional proofs that save students (and you!) from that typical frustration as they learn to write proofs. This added in-between step has transformed so many Geometry classrooms. It's a game-changer! This full unit pack (78 pages plus 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 images for more information and sample pages. The zip file includes a presentation and a set of printables (PDF format). 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. Reviews from Other Geometry Teachers: This makes proofs much easier to understand!! Great resource. The idea was perfect for what I was teaching. The flow from algebraic proofs to geometric proofs help students understand. Proofs have been difficult for me to teach, but NO MORE! This is well organized and I had my first successful year explaining proofs, FINALLY! Thank you! So much better than I even anticipated, This will revolutionize the way I teach proofs this year, THANK YOU! This is a topic that is quite challenging for many students. I thought it was very useful guiding students through the process of solving proofs. Nice product. This was such a helpful resource! The idea of introducing students to substitution and transitivity with the algebraic proofs was smart and students caught on. Also, we loved the little birdie in the slides and the students ended up naming him "Tessie" :) It's all there! Awesome unit. Wish I had this the first time I taught two-column proofs (would have gone a lot smoother)! I LOVE this. I'm doing it with my Honors Geo classes right now. The PPT presentation is lovely, and the handouts are pleasant. The order is great. This is my favorite proofs unit. This will be my 1st year teaching high school geometry. Proofs can be difficult to teach and these activities will really help. I liked this unit so much that I bought the entire geometry bundle. This was the best unit I've seen on proofs in my 4 years of teaching. For the first time ever I think I did proofs some justice and the kids actually got it. Thanks so much!!! It has been quite a while since I've done Geometry Proofs and I'm subbing for a friend to help out in teaching this unit. The students are remedial and I REALLY need help. I've looked over many of the units online and THIS is BY FAR the most simplified and best help I've found. THANK YOU!!! This is great. My students are working through the materials with a better understanding than ever before. Well worth the money! Thank you!
