This lesson is designed to help geometry students discover characteristics of quadrilaterals. The lesson should be used after students have been taught the basic definitions of trapezoids, parallelograms, rectangles, squares, and rhombi. Technology-based and hands-on activities are included.

Handouts with drawings of quadrilaterals (see attachment), scissors, rulers, protractors

Microsoft PowerPoint software, Geometer's Sketchpad software

Students should be able to recognize and define: quadrilateral, trapezoid, parallelogram, rectangle, rhombus, square.

1.)Determine Quadrilateral Characteristics. Divide the class into 5 (or 10) groups and give each group a sheet with one quadrilateral on it (see attachment). Students need to name their quadrilateral, as specifically as possible, and then cut it out. Use rulers and protractors to draw and measure diagonals and angles. Find as many relationships as possible between opposite sides, opposite angles, and diagonals. Instruct group with trapezoid to draw and find relationships with the median.

2.)Recording Quadrilateral Characteristics. Distribute graphic organizers (see attachment). Students record each characteristic inside the quadrilaterals as the groups report their findings. Use Parallelogram Chart (see attachment) as a transparency to then check mark each characteristic as a reinforcement. Teacher leads students to recognize relationships between quadrilaterals.

3.)Proving Quadrilateral Characteristics. In the computer lab using Geometer's Sketchpad, students construct a parallelogram, rectangle, rhombus and square. Students then use the measurement tool and completed graphic organizer to prove each quadrilateral by both definition and specific characteristic. Example: Students cannot use parallelogram characteristic to prove that a figure is a rectangle. (NOTE: In Sketchpad directions attached, tool bar commands are highlighted and use of top menu bar is in upper case.)

4.)Reviewing Quadrilaterals. Use the Powerpoint Jeopardy-type game attached, "Name that Quad", to review characteristics.

Assessment will be by a Quadrilateral Quiz/Test in which students are given a characteristic and then must determine all quadrilaterals to which it applies and a Sometimes/Always/Never activity in which students are given a statement and must respond with Sometimes/Always/Never. Example: A rectangle is ? a square. (answer: sometimes)

See "Geometrica Fights Back" lesson on ALEX.