Angles of Elevation and Depression

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Angles of Elevation and Depression

• 11.3

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Definitions

• Angle of Elevation or Depression If B is above
  A, then the angle of elevation from A to B is the
  acute angle formed by AB and a horizontal line
  through A. The angle of depression from B to A is
  the acute angle formed by BA and a horizontal
  line through B.

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Elevation or Depression?
B
2
A
1
3
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The Archway

• To find the height of Delicate Arch in Arches
  National Park Utah, a surveyor places a
  theodolite at the same level as the bottom of the
  arch. From there she measures the angle of
  elevation to the top of the arch. She then uses a
  stell tape to measure the distance from her to
  the spot directly under the arch. The results of
  her survey are shown on the diagram How tall is
  the arch?

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How tall?
X ft
48
36ft
5ft
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Homework

• P. 558 1-14