Applet Review: Angle Sums

Angle Sums. NCTM Illuminations. http://illuminations.nctm.org/ActivityDetail.aspx?ID=9

The objective of this applet is for students to be able to manipulate shapes. Also students will be able to identify the relationship between the number of sides/angles in a shape and the sum of the angles formed by the shape. Students will also be able to identify the relationship between angles within a shape and the concept that the sum of the angles within a shape is constant. The applet allows students to choose a shape (triangle, quadrilateral, pentagon, hexagon, heptagon, octagon) and then manipulate the lines and angles by clicking and dragging any point of the shape. Angles are numbered and color coded with a key on the right side of the shape. The key contains the exact measurement of each angle and the sum of all angles. The applet is simple and easy to use, as well as colorful and atheistically appealing. There are no complications, this applet is very straightforward.

I think that this applet could be useful in student learning, although it would need to be used in a very structured, supervised manner. With little guidance, or thought provoking questions, many students may just "play" with the application, gaining few mathematical understandings. A teacher could use this tool along with a mini lesson or a "record" sheet for students to record angle measurements. A teacher-led conclusion or discussion of learning after using the applet would be crucial to students' learning. Viewing with a critical eye, I feel that this applet is a bit too simplistic and boring. It does not seem to engage students in learning, and in depth thinking seems to be optional when using this applet, as it does not require any computations or problem solving to use the tool.