Education Technology

Special Midpoint Quadrilaterals

Published on 10/17/2005

Activity Overview

Midpoint Quadrilaterals are quadrilaterals that are formed when consecutive midpoints of a quadrilateral are connected. This activity will use Cabri® Jr. to investigate what properties an exterior quadrilateral has if its midpoint quarilateral has some special properties of its own.

Before the Activity

Teacher should discuss the concept of midpoint quadrilaterals with the class.

During the Activity

Use TI-Navigator™ to send files MIDQUAD.8xv, MIDQUAD1.8xv, MIDQUAD2.8xv, and MIDQUAD3.8xv to the students' calculators.
The students will use Cabri Jr. to investigate the properties of the exterior quadrilaterals in files MIDQUAD1, MIDQUAD2, & MIDQUAD3 -- each has a midpoint quadrilateral with special properties of its own.
The file MIDQUAD.8xv is actually a LearningCheck™ file that can be used to review these properties with the students.

After the Activity

The file Mid_Quads_HW.doc contains a page for students to provide 3 proofs for each of the special midpoint quadrilaterals. An answer key is also included in this document.