Wednesday, March 14, 2007
Geometry (Class 58)
Announcement
Quiz Friday focusing on Chapter 8 Lessons 3 to 5 and Chapter 9 Lesson 1
Overview
Today we start the development of the three key trigonometric ratios, what they mean, where they come from, why they work, and how to put them to work.
Textbook Sections
§9.5 (Txt. p.558) Trigonometric Ratios
Key Attitudes
Mathematics is about justification.
Key Ideas
If two right triangles have one additional congruent pair of angles, then the triangles are similar.
If two right triangles are similar, then the ratios of their sides are equal.
If you know the measure of one non-right angle in a right triangle and the length of one side, then you can find the lengths of the other sides and the measures of the other angles.
If you know the length of two sides of a right triangle, then you can find the lengths of all of the sides of the right triangle
Key Skills
Using trigonometric ratios to solve right triangles.
Handouts
Chapter 9-Lesson 2: An Introduction to Right Triangle Trigonometry
Chapter 9-Lesson 2: Trigonometric Ratios Record Sheet
Assignment
§9.1 (Txt. p.531)#13, 14, 17, 18, 19, 20, 33
§8.6 (Txt. p.503)#23, 24
Permalink