Look out for the rocks

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Look out for the rocks!

• Application of Trigonometry
• by Pete Anderson

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Did you know . . .
the Lighthouse of Alexandria was one of the
Seven Wonders of the Ancient World?
Web Source
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Problem
If a ship can spot the top of a lighthouse at an
angle of elevation of 10 and the height of the
lighthouse is know to be 150 feet above sea
level, then how far from the lighthouse is the
ship?
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Create a Diagram
If a ship can spot the top of a lighthouse at an
angle of elevation of 10 and the height of the
lighthouse is known to be 150 feet above sea
level, then how far from the lighthouse is the
ship?
10
150 feet
X
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Writing an Equation
pneumonic
SOH
sin
CAH
cos
T
OA
tan
O
H
A
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Solving the Equation
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Verify Your Solution
?
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Quiz
If a lighthouse keeper spots a ship at an angle
of depression of 12 and the height of the
lighthouse is known to be 175 feet above sea
level, then how far from the lighthouse is the
ship?

• 37 feet
• 179 feet
• 823 feet
• 842 feet

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Solution to Quiz
C