Wednesday, January 10, 2007
Geometry (Class 40)
Overview
Today we continue to work on the proofs concerning the properties of parallelograms. In addition we may start our second lesson for Chapter 6 (these lessons tend to take more than one class) which focuses on learning how to name the various types of quadrilaterals we encounter.
Textbook Sections
§6.3 (Txt. p.338) Proving Quadrilaterals are Parallelograms
§6.4 (Txt. p.347) Rhombuses, Rectangle, and Squares
Key Attitudes
Mathematics can be a tool for investigating and uncovering facts.
Investigating requires creativity and persistence.
If you don’t first succeed, try, try again.
Key Ideas
A parallelogram has:
two pairs of congruent opposite sides
two pairs of congruent opposite angles
all adjacent angles are supplementary
diagonals which bisect each other
Two lines can be proven to be parallel by various methods:
1) by showing that alternate interior angles are congruent
2) by showing that alternate exterior angles are congruent
3) by showing that corresponding angles are congruent
4) by showing that consecutive interior angles are supplementary
Key Skills
Proving triangles are congruent
Proving lines are parallel
Proving a quadrilateral is a parallelogram
Writing two-column proofs
Handouts
Chapter 6, Lesson 2: Types of Quadrilaterals
Assignment
Lesson 6.3 Practice A #1-8, 12-13
Final Review Chapter 3
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