Transcript 8-5 Angles of Elevation and Depression

Angles of Elevation and Depression
LESSON 8-5
Additional Examples
Describe
1 and
2 as they relate to the situation shown.
One side of the angle of depression is a horizontal line.
1 is the angle of depression from the airplane to the building.
One side of the angle of elevation is a horizontal line.
2 is the angle of elevation from the building to the airplane.
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HELP
GEOMETRY
Angles of Elevation and Depression
LESSON 8-5
Additional Examples
A surveyor stands 200 ft from a building to measure its height
with a 5-ft tall theodolite. The angle of elevation to the top of the
building is 35°. How tall is the building?
Draw a diagram to represent the situation.
x
tan 35° = 200
Use the tangent ratio.
x = 200 • tan 35°
200
35
Solve for x.
Use a calculator.
So x
140.
To find the height of the building, add the height of the theodolite,
which is 5 ft tall.
The building is about 140 ft + 5 ft, or 145 ft tall.
HELP
Quick Check
GEOMETRY
Angles of Elevation and Depression
LESSON 8-5
Additional Examples
An airplane flying 3500 ft above ground begins a 2° descent
to land at an airport. How many miles from the airport is the airplane
when it starts its descent?
Draw a diagram to represent the situation.
sin 2° =
x=
3500
2
5280
3500
x
Use the sine ratio.
3500
sin 2°
Solve for x.
Use a calculator.
Divide by 5280 to convert
feet to miles.
The airplane is about 19 mi from the airport when it starts its descent.
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HELP
GEOMETRY