Download 8-4: Angles of Elevation and Depression

8-4: Angles of Elevation
and Depression
Expectations:
1) G1.3.1: Define and use sine, cosine and
tangent ratios to solve problems using
trigonometric ratios in right triangles.
2) Determine the exact values of sine, cosine
and tangent for various angle measures.
Daily Quiz 5/16:
The hypotenuse of the right triangle
ABC shown below is 17 feet long. The
cosine of angle C is 3/5. How many feet
long is the segment AC?
A.
B.
C.
D.
E.
6
10.2
12
15
28.3
B
17
A
C
Angles of Elevation
If a situation can be represented
by a person looking up, we have
an angle of elevation.
Angles of elevation are always
measured off of the horizontal –
never the vertical!!!
Angle of Elevation
Angles of Depression
Angles of depression represent
situations in which a person
looks down.
Angles of depression are always
measured off of the horizontal –
never off of the vertical!!!
Angle of Depression
Charo is 50 feet from a totem pole
and looks up at an angle of 75°
to see the top of the pole. If Charo
is 5 feet tall, how tall is the totem
pole?
When measured from a point on the ground that is a
certain distance from the base of a cell phone tower, the
angle of elevation to the top of the tower is 41°. The
height of the cell phone tower is 200 feet. What is the
distance, in feet, to the cell phone tower?
A.
B.
C.
D.
E.
200 tan 41
200 sin 41
200 cos 41
200 sec 41
200 cot 41
200 feet
(tower)
41°
Distance (?)
Betty is at the top of a sledding
hill. If she looks down at 32° to
see the bottom of the hill and the
elevation of the hill is known to be
100 feet, how long is the sled
run?
Daily Quiz 5/17
1.
Determine the value of x.
x
34
°
12.5
2.
Determine the value of θ.
θ
7
10
A pilot is flying at an altitude of 2,500
feet. If she can see the beginning of
the landing strip by looking down at an
angle of 6°, what is the ground
distance from the airport?
Betty is standing on the top of a zip line
looking down at Claire at an angle of 18
degrees. If the elevation of the top of the
zip line is 65 feet higher than at the
bottom, how long is the cable for the zip
line?
Assignment
pages 423 – 425,
# 17 – 27 (odds), 30, 31, 33 a & b,
35 – 43 (odds)