February 22, 2009
How far, to two significant digits, is he from the base of the cliff?
Nora asked:
The captain of a ship wants to determine his distance from shore. Seeking familiar landmark, he finds a 90 feet high lighthouse on top of a cliff. He sights both the top and bottom of the lighthouse. the measures of the two angles of elevation are 46 and 39. How far to two significant digits, is he from the base of the cliff?
The captain of a ship wants to determine his distance from shore. Seeking familiar landmark, he finds a 90 feet high lighthouse on top of a cliff. He sights both the top and bottom of the lighthouse. the measures of the two angles of elevation are 46 and 39. How far to two significant digits, is he from the base of the cliff?
a) 325 feet b)300 feet c)425 feet or d) 400 feet?
Thank you for your help
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Comments on How far, to two significant digits, is he from the base of the cliff? »
let height be h.
By trigonometry we have
h h
———– (minus) ———– = 90.
tan 39 tan 46
On solving h as 334 feet
which is closed to option a above.
Thank you.
The answer should be 400 feet.