Wednesday, November 15, 2006
Geometry (Class 27)
Overview
§4.7 (p.243) Triangles and Coordinate Proof
Review for Midterm
Today we continue our work with Analytic Geometry.
We also spend a significant portion of the class working review problems in our groups in order to further prepare for the mid-term exam on Friday November 17.
Key Ideas
Use the coordinates to your advantage!
The main tools that can be used when writing coordinate proofs are the distance formula (to show two segments are of equal length and hence congruent), the midpoint formula (to find the location of the midpoint), the slope of a line (to show lines are parallel or perpendicular), and the Pythagorean Theorem (to show that a triangle is a right triangle).
In order to make the proof as easy as possible, place the figure wisely. For instance, place a vertex at the origin, or use the axes to form a right triangle, or use the symmetry of an isosceles triangle to your advantage by placing the base on the x-axis and the vertex angle on the y-axis.
Vocabulary
No new vocabulary
Assignment
§4.7 (Txt. p.247) #11-13, 18, 24-26
Chapter 4 Test (Txt. p.255) 10 most important problems-- you pick them!
Chapter 4 Standardized Test (Txt. p.256) 10 most important problems-- you pick them!
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