In this activity, students construct medians, altitudes, angle bisectors, and perpendicular bisectors of triangles. They then drag the vertices to see where the intersections of the segments lie in relation to the triangle, and they measure distances to identify relationships. They see that the intersection of the angle bisectors (incenter) and that of the perpendicular bisectors (circumcenter) can be used, respectively, to draw a circle inscribed in and circumscribed about a triangle.

Download the attached PDF and look over the information on the first page. Download and distribute the attached student TI-Nspire document (.tns file) and student worksheet for use during the activity.

Discuss the material from the activity pages and worksheet with students as needed.

Encourage students to summarize what they have learned from completing the activity. If desired, discuss the extension with students.