Name: ________________________________
Geometry
Trigonometry Unit
Instructor: Mr. Grant
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Trigonometry Unit Instructions
1.
Complete the Pre-Journaling Assignment.
2.
View the Introductory Video.
3.
Preview Worksheet 1 “What I Need To Know” material and
video(s)
4.
Complete the odd numbered problems on Worksheet 1.
Refer back to “What I Need To Know” materials, Mr. Grant, or
other students for help.
5.
Every Day – Enter into Activity Log the date and a note on
how much of what you accomplished for the day.
6.
Check your answers.
7.
Have Mr. Grant select several even numbered problems to
test you out of the worksheet.
8.
Move on to Worksheet 2 when Mr. Grant has graded and
signed off on Worksheet 1.
9.
Repeat process (i.e., steps 3, 4, 5, 6, and 7) for Worksheet 2,
Worksheet 3, and Worksheet 4.
10. Complete Trigonometry Unit Exam.
11. Complete the Post-Journaling Assignment.
12. Hand in Trigonometry Unit packet for review by Mr. Grant.
13. Move on to next unit.
14. Remember to enter into Activity Log the date and a note on
how much of what you accomplished for each day.
15. Other Notes:
a. Mr. Grant’s Geometry Wikispace: http://mathb.hyde.wikispaces.net/Geometry-Grant
i. Here you will find worksheet answers and be able to
access the hyperlinks.
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Trigonometry Journaling - Pre
Do you think geometry is an important subject for you to study? Why or
why not?
When I study for a test I…
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Trigonometry: Introductory Video
Introductory Video:
SOH CAH TOA - Trigonometric Ratios
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Trigonometry: What I Need to Know
Worksheet 1: Trigonometric Ratios
Worksheet 2: Solving Right Triangles
Worksheet 3: Multi-Step Trigonometric Problems
SOH CAH TOA
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"SOHCAHTOA" is a helpful mnemonic for remembering the definitions of the trigonometric functions sine, cosine, and
tangent i.e., sine equals opposite over hypotenuse, cosine equals adjacent over hypotenuse, and tangent equals
opposite over adjacent,
(1)
(2)
Helpful Videos: Basic Trigonometry 1
Basic Trigonometry 2
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Trigonometry: What I Need to Know
Worksheet 4: Trigonometry and Area
Area of Triangle and
Parallelogram Using
Trigonometry
Topic Index | Algebra2/Trig Index | Regents Exam Prep Center
We are all familiar with the formula for the area
of a triangle,
,
where b stands for the base and h stands for the
height drawn to that base.
(the lettering used is of no importance)
In the triangle at the right, the area could be expressed as:
Now, let's be a bit more creative and look at the diagram again. By using the right triangle on the
left side of the diagram, and our knowledge of trigonometry, we can state that:
This tells us that the height, h, can be expressed as bsinC.
If we substitute this new expression for the height, we
can write the triangle area formula as:
(where a and b are adjacent sides and C is the included angle)
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We have just discovered that the area of a triangle can be expressed using the lengths of two
sides and the sine of the included angle. This is often referred to as the SAS Formula for the area
of a triangle.
The "letters" in the formula may change from problem to problem, so try to remember the
pattern of "two sides and the sine of the included angle".
We no longer have to rely on a problem
supplying us with the length of the altitude
(height) of the triangle in order for us to find the
area of the triangle. If we know two sides and
the included angle, we are in business.
"Wow! A trig area formula for triangles!!!"
Example 1:
Given the triangle at the right, find its area.
Express the area rounded to three decimal
places.
Be careful!!! When
using your graphing
calculator, be sure that
you are in DEGREE
Mode, or that you are
using the degree
symbol.
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Trigonometry Journaling - Post
What are three things I have learned about Trigonometry?
If I were better at math, I would…
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Trigonometry Unit Activity Log
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Mr. Grant Sign-Off: ________________________________ Review Grade: _________
Trigonometry Exam Grade: __________
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