Sophia Learning
Sophia: Using Corresponding Parts of Congruent Triangles
This lesson will demonstrate the use of CPCTC in triangle congruency proofs.
Illustrative Mathematics
Illustrative Mathematics: g.co Reflections and Isosceles Triangles
This task has learners link their intuitive notions of symmetries of a triangle with statements proving that said triangle is unmoved by applying certain rigid transformations. The mechanism through which students do this is via...
Jim Loy
Jim Loy's Mathematics Page: Congruence of Triangles
Find explanations of the ways to prove triangles are congruent. There is a link for Congruence Of Triangles, Part II to find the proofs of some ways to prove congruence of triangles from other postulates (i.e. Assume SAS prove ASA).
Sophia Learning
Sophia: Cpctc: Lesson 2
This lesson will demonstrate the use of CPCTC in triangle congruencey proofs. It is 2 of 4 in the series titled "CPCTC."
Khan Academy
Khan Academy: Proofs With Transformations
Explore different ways of proving some theorems about lines and angles. Some transformations are used.
Oswego City School District
Regents Exam Prep Center: Theorems and Postulates for Geometry
Here is a partial list of theorems, postulates, and properties.
ClassFlow
Class Flow: Cpctc
[Free Registration/Login Required] This flipchart looks into the concept of CPCTC with triangles, using proofs. This flipchart has interactive parts, video, and voting.