Education Technology

Geometry: Triangle Sum Theorem

by Texas Instruments


Make a conjecture about the sum of the measures of the interior angles of a triangle and prove the Triangle Sum Theorem



  • adjacent angles
  • interior angles

About the Lesson

This “create your own” activity is designed to be student-centered, with the teacher acting as a facilitator while students work cooperatively. The time varies for this activity depending on whether the TI-Nspire document (.tns file) is provided or created by the students.