Education Technology

ASA Triangle Congruence

Published on 01/25/2007

Activity Overview

1.Construct an triangle and select two angles and the contained side to copy to a second triangle. 2.Measure sides and angles to visualize congruence properties 3.Try to alter the properties of their construction by moving the vertices of the original triangle

Before the Activity

Each student should have access to TI-84 Plus Family calculator, Cabri. Jr. and the attached .pdf file.

During the Activity

This activity will help students visualize the construction of congruent triangles and conceptualize properties of congruent triangles through measurement and movement of their construction. Extensions When the first circle was drawn through point D, there are two possible points of intersection. Would the construction work just as well if you had selected the second point? Would it matter if the triangle were right angled? What about obtuse or isosceles?

After the Activity

Review student answers:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary