This activity works with a PowerPoint presentation to have students answer questions as to what method a pair of triangles can be proven congruent: SSS, SAS, ASA, AAS, HL
Before the Activity
Have students log into TI-Navigator™. While going through this process, review with students the ways one can prove triangles congruent.
During the Activity
Begin Powerpoint presentation as students open and begin LearningCheck™ file, Congruent Triangles.edc. Teacher proceeds through the slideshow as students record answers in LearningCheck. Leave each slide up long enough for students to choose all valid methods of proving congruence. Some examples have more than one appropriate method.
Note: This activity could also be done using Quick Poll, instead of LearningCheck. The teacher would assign multiple choice letters to the various congruence theorems, and could write these on the board to be used repeatedly for all examples.
After the Activity
Proceed through slideshow in PowerPoint once more to discuss why the correct methods work for each figure.
Stress the importance of alternate interior angles created by parallel lines, as well as the reflexive property.