Curated OER
Verifying Segment Relationships
In this verifying segment relationships worksheet, 10th graders solve 3 different proofs by verifying the segment relationship in each. They complete each proof given a specific statements supporting the statement with reasons. Then,...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Faq About Proofs
This site provides links to questions sent in to Dr. Math about proofs. Topics covered include what proofs are, how to understand them, and how to build them, and much more. Be sure to click on the links which you believe may be helpful.
CK-12 Foundation
Ck 12: Geometry: Two Column Proofs
[Free Registration/Login may be required to access all resource tools.] Write two-column proofs.
CK-12 Foundation
Ck 12: Geometry: Two Column Proofs Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to write two-column proofs, and provides proofs for the Right Angle Theorem, Same Angle Supplements Theorem, and Vertical Angles...
Wolfram Research
Wolfram Math World: Two Column Proof
MathWorld gives a discussion of the use of two-column proofs by high school and middle school students and its relevance to mathematicians.