Flexing Our Bisectors
Objective: SWBAT use dynamic geometry software to construct a (segment) bisector and verify its properties. Students will understand how learning constructions helps them to understand the properties of geometric objects.
Big Idea: What are the properties of a bisector? Students see for themselves--and learn the advantages of dynamic geometry software.
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Lesson Opener
Team Warm-up
The Warm-Up prompt is a leading question: I ask students to consider the limitations of pencil-and-paper constructions, so that I can point out the advantages of dynamic geometry software.
This lesson opener follows our Team Warm-up routine, with students writing individual answers in their Learning Journals. I display the prompt using the Slideshow for the lesson.
Goal-Setting
Displaying the lesson Agenda and Learning Targets, I tell the class that today we will learn how to use dynamic geometry software to construct a bisector and investigate its properties. The software allows us to construct a figure, then move its vertices or change some of its measurements to see how this effects the figure.
The application we will be using is a freeware program called WinGeom.
Team Size-Up
The lesson close follows our Team Size-Up routine. The Lesson Close prompt asks students to name some of the advantages of dynamic geometry software.
Homework
Homework Set 2 problem #28 gives students another chance to use constructions to examine the properties of bisectors. Problem #29 provides practice with vocabulary and geometric notation. In Problem #30, students follow instructions (written using geometric vocabulary and notation) to construct an equilateral triangle inscribed in a circle.
