Wednesday, March 19, 2008
Geometry (Class 63)
Announcements
Test Friday. Focus will be on Chapter 8: Lesson 1 through Chapter 9: Lesson 2
Lesson Title
Special Right Triangles 2
Overview
In today’s class our warm-up continues to extend the skills and concepts necessary to find surface area and volume. Our focus today is on pyramids and we see how the work we did with the Yang Ma can be generalized to all pyramids. During the lesson part of the class we wrap up the development of special right triangles.
Textbook Sections
§9.4 (Txt.p.551) Special Right Triangles
Vocabulary
special right triangle
isosceles right triangle
45-45-90 triangle
30-60-90 triangle
Key Attitudes
Math is about thinking creatively.
Key Ideas
A special right triangle can be created from a square. This results in an isosceles right triangle whose angle measures are 45˚, 45˚, and 90˚.
A special right triangle can be created from folding an equilateral triangle. This creates a triangle with 30˚, 60˚, and 90˚ angles- a 30-60-90 triangle
30-60-90 and 45-45-90 triangles are special because we can easily related the lengths of the sides of the triangle to the measures of the interior angles of the triangle.
Key Skills
Recognize special right triangels.
Explain what makes a right triangle special.
Justify the relationships between angle measures and side lengths in special right triangles.
Use the relationships between the angle measures and side lengths in special right triangles to find missing side lengths or angle measures. http://www.youtube.com/watch?v=_eBIuP9pugM
Simplify radicals including rationalizing the denominator. http://www.youtube.com/watch?v=N8MkTuLlgOg&feature=email
Turn-In (#62)
§9.2 (Txt. p.538) 7-9, 16-18, 25-27, 31
Chapter 8- Lesson 7
Handouts
Chapter 12- Solid 5 (Square Based Pyramid)
Assignment
§9.4 (Txt. p.554) #12-17, 24-27
§9.3 (Txt. p.546) #8-10, 14-17
Disclaimer- The assignment as stated in class is the official assignment. Every effort is made to keep this posting accurate, but you should refer to what was stated in class as the final word.
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