Monday, May 11, 2009
Geometry (Class 78)
Lesson Title
Right Triangle Ratios (5)
Overview
The opener for today focuses on equations of lines. Students will then learn how to use their calculator instead of a trig. table to solve problems, Students will then have time to work a new set of problems requiring the creative use of trigonometry. As time permits we will begin our study of the relationship between angles, segments, and circles.
Textbook Sections
§9.5 (Txt. p.558) Trigonometric Ratios
Vocabulary
right triangle
leg
hypotenuse
special right triangle
trigonometry
isosceles right triangle
equilateral triangle
equiangular triangle
45-45-90 triangle
30-60-90 triangle
standard position
reference angle
adjacent side
opposite side
hypotenuse
ratio
trigonometry
Key Attitudes
Math is about building up understanding one idea at a time.
Key Ideas
If the length of two sides of a right triangle are known, then you can figure out the measure of the angles of the triangle using trigonometric ratios.
If the length of one side and the measure of one angle in a right triangle are known, then you can figure out the measures of the other sides and angle using right triangle trigonometry.
All right triangles which have equal acute angles will be similar and hence the ratios of theirs sides (opp./adj., opp/hyp, adj/hyp) will be equal.
The terms sine, cosine, and tangent are code names for the ratios of sides of right triangles.
Key Skills
I can translate between the ratios of sides of right triangles and their code names (sine, cosine, tangent).
I can find the measure of the missing sides of a right triangle when given the measure of one acute angle and the measure of one side.
I can find the measure of an acute angle of a right triangle when given the measures of two sides of the right triangle.
Turn-In (#77)
Trig. Practice Problems
Handouts
Chapter 9: Lesson 6- Using your calculator
Assignment
Txt. p.562 #16-19, 31-33, 36-38
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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