ADV MT 6.2 (continued)
Angle of Elevation
The angle above horizontal that an observer must look to see an object that is higher than the observer. Angle of Depression
The angle below horizontal that an observer must look to see an object that is lower than the observer. *At top of object looking down
*On the ground looking up!
*The angle of elevation is congruent to the angle of depression.
Hint: ALWAYS draw a picture!
Sep 28­8:00 AM
If you are looking at an object above the horizon then the angle between the horizontal and your line of sight is the angle of elevation. If you are looking at an object below the horizon then the angle between the horizontal and your line of sight is the angle of depression.
Sep 28­8:47 AM
John wants to measure the height of a tree. He walks exactly 100 feet from the base of the tree and looks up. The angle from the ground to the top of the tree is 33º . How tall is the tree?
h
33o
100 ft
A building is 50 feet high. At a distance away from the building, an observer notices that the angle of elevation to the top of the building is 41º. How far is the observer from the base of the building?
In the diagram the lines of sight from the ground upwards and from the top of the building downwards are indicated in red. From the diagram you can see that the angle of elevation and the angle of depression are congruent.
http://regentsprep.org/Regents/math/rtritrig/LtrigW.htm
Sep 28­8:56 AM
An airplane is flying at a height of 2 miles above the ground. The distance along the ground from the airplane to the airport is 5 miles. What is the angle of depression from the airplane to the airport?
2 mi
5 mi
Sep 28­8:37 AM
The angle of elevation of the top of a pole measures 48° from a point on the ground 18 ft away from its base. Find the height of the flagpole.
An airplane is flying at an altitude of 1000 m. From the plane, the angle of depression of the airport on the ground is measured as 15°. What is the distance from the plane to the airport?
A bird sits on top of a lamppost. The angle of depression from the bird to the feet of an observer standing away from the lamppost is 35o. The distance from the bird to the observer is 25 meters. How tall is the lamppost?
Sep 28­8:40 AM
Sep 28­8:55 AM
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