Lesson 8: Using Trigonometry to Find Missing Sides

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Math 10C Module 1 Lesson 7

Module 1 Part 2: Trigonometry

This section checks to see if you have the prerequisite knowledge and skills to be able to complete this lesson successfully.

Are You Ready?

Complete these questions in your course folder (binder). If you are experiencing difficulty, you may want to use the information and the multimedia in the Refresher section to clarify concepts before completing these exercises.

1. Given the triangle below, complete the following:

a. the side opposite K is labelled as lower case _______
b. the side adjacent K is labelled as lower case _______
c. the side opposite L is labelled as lower case _______
d. the side adjacent L is labelled as lower case _______
e. the hypotenuse is labelled as lower case______

State the following as ratios using lower case letters:
f. sin K =
g. cos K =
h. tan K =
i. sin L =
j. cos L =
k. tan L =

2. State the sin, cos and tan for both angle X and Y in the triangle below. State your answers in both fractional and decimal form ( rounded to the nearest thousandth).

a. sin X =
b. cos X =
c. tan X =
d. sin Y =
e. cos Y =
f. tan Y =

3. Use your calculator to find the following answers. Round your answers to the nearest thousandth.

a. sin 42^o =

b. cos 85^o =

c. tan 66^o =

4. Solve the following ratios for the missing variable.

Once you have completed these exercises to the best of your ability, use the provided answer link to check your work.

Answers

If you feel comfortable with the concepts covered in the questions, move forward to Explore. It is also RECOMMENDED you work through the resources in the Refresher to review these important concepts before continuing through the lesson.

Refresher

Shape and Space: Trigonometry provides a good review before you begin solving for missing sides. On the right-hand side of the website, click on “Interactive.” When you are finished, choose “Video.”