8.4 Angles of Elevation and Depression
Suppose a person on the ground sees a hot-air balloon gondola
at a 38 degree angle above a horizontal line.
This angle is the angle of ______________________.
At the same time, a person in the hot-air balloon sees the
person on the ground at a 38 degree angle below a horizontal
line.
This angle is the angle of _____________________.
The angle of elevation is ______________________ to the
angle of depression because they are
____________________ _______________ angles.
Example 1: Identifying Angles of Elevation and Depression
Describe each angle as it relates to the situation shown.
1.
2.
1
4
Got It?
1.
2
2.
3
Example 2: Using Angles of Elevation and Depression
1. One method that meteorologists could use to find the height of a layer of clouds above the
ground is to shine a bright spotlight directly up onto the cloud layer and measure the angle
of elevation from a known distance away. Find the height of the cloud layer in the diagram to
the nearest 10 m.
2. A firefighter on the ground sees fire break through a window near the top of the building.
There is a voice contact between the ground and firefighters on the roof. The angle of
elevation to the windowsill is 28 degrees. The angle of elevation to the top of the building is
42 degrees. The firefighter is 75 ft from the building and her eyes are 5 ft above the
ground. What roof-to-windowsill distance can she report to the firefighters on the roof?
3. From the top of a lighthouse, the angle of depression to a buoy is 25 degrees. If the top of
the lighthouse is 150 feet above sea level, find the distance from the buoy to the foot of
the lighthouse.
4. A surveyor is 300 ft from the base of an apartment building. The angle of elevation to the
top of the building is 24 degrees, and her angle-measuring device is 5 ft above the ground.
Find the height of the building.
5. A 5-foot-tall woman stands 15 feet from a statue. The must look up at an angle of 60
degrees to see the top of the statue. How tall is the statue?