Download Sine, Cosine and Tangent Ratios – Sections 9

Mrs. Scott
Modern Geometry
Name:___________________________________
Date:____________________________________
9.1/9.2/9.3 - Sine, Cosine and Tangent Ratios and Angles of Elevation/Depression
Learning Objectives
1. To use the Sine, Cosine and Tangent ratios to determine side lengths in triangles.
2. To use angles of elevation and depression to solve problems.
SOH CAH TOA
sin angle
= _____
cos angle
= _____
tan angle
= _____
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Example 1: Use the triangle to write each ratio.
sin T =
cos T =
tan T =
sin G =
cos G =
tan G =
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Quick Check: Write the sine, cosine and tangent ratios.
When does the sine = cosine?
What is the relationship between tan X and tan Y?
Example 2:
A 20-ft wire supporting a flagpole forms a 35° angle with the flagpole. To the nearest foot, how
high is the flagpole?
Example 3:
To measure the height of a tree, Alma walked 125 feet from the tree and measured a 32° angle
from the ground to the top of the tree. Estimate the height of the tree.
Example 4:
Example 5:
Example 6:
Angles of Elevation and Depression
__________________________
__________________________
In your own words, what is the angle of elevation?
In your own words, what is the angle of depression?
What is the relationship between an angle of elevation and an angle of depression?
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Example 2:
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Quick Check: