MTED 2800/3900

Fall 2004

Read:

- Saturday Math Club
*Summary of Lesson from Jan. 3 & Assignment for Jan 10;* - Saturday Math Club
*Summary of Lesson from Jan. 10 & Assignment for Jan. 17*.

These summaries recap two introductory lessons with advanced seventh-graders in which Geometer's Sketchpad was used as a tool.

Part I

- Go through the materials using Sketchpad to re-enact each situation. Play with the constructions and reflect on the instructional interactions described in the summaries.
- Re-read the discussions. If you only read the discussions without having played with the situation then you will not have a clear sense of these students' experiences, and hence you will not have a clear sense of how the discussions were grounded in the studentsÕ experiences.
- What "big ideas" did these students encounter? (Some of these ideas might not have been discussed explicitly, but are there nevertheless.)

- Part II Practicing basic constructions.
- Practice these constructions using Sketchpad. Click on the links to download GSP sketches that get you started. :
- Given a segment, a line, and a point on the line, duplicate the segment so that the duplicate is on the given line with the given point as one endpoint.
- Given an angle, a line, and a point on the line, duplicate the angle so that the angle has one side on the given line the given point as its vertex.
- Duplicate a triangle given three sides
- Duplicate a triangle given two sides and the angle they form.
- Duplicate a triangle given one side and two angles that contain that side.

- Play with the AAS Ambiguity sketch to understand why "Angle-Angle-Side" is an ambiguous relationship and is sufficient to guarantee similarity of two triangles, but not congruence.