Download Vocabulary - Hartland High School

Section 7.6 Apply the Sine and Cosine Ratios
Goal  Apply the Sine and Cosine Ratios
Sine Ratio
Let ∆ABC be a right triangle with
acute A.
sin  
opposite
BC

hypotenuse AC
Cosine Ratio
Let ∆ABC be a right triangle with
acute A.
cos  
adjacent
AB

hypotenuse AC
Example 1: Find sin U and sin W. Write each answer as a fraction and as a decimal rounded to four
places.
Example 2: Find cos S and cos R. Write each answer as a fraction and as a decimal rounded to four
places.
Example 3: You walk from one corner of a basketball court to the opposite corner. Write and solve a
proportion using a trigonometric ratio to approximate the distance of the walk.
Example 4: You are at the top of a roller coaster 100 feet above the ground. The angle of depression
is 44°. About how far do you ride down the hill?
Section 7.6 Apply the Sine and Cosine Ratios
Example 5: A railroad crossing arm that is 20 feet long is stuck with an angle of elevation of 35° Find
the lengths x and y.
Checkpoint: Use a sine, cosine, or tangent ratio to find the length of the sides in the triangles below.
a.
b.
x
10
40º
22º
10
x
d. Find m, x, and y.
15
28º
y
mº
x
68º
c.
10
x