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Math Homework Help ... angles.?
From a point in the street between two buildings the angles of elevation of the tops of the buildings are 45degrees each. When the observer moves 21 feet toward one of the buildings, the angles of elevation are 25degrees and 65degrees respectively. How high is each buildings?
Please show work. Thanks!
2 Answers
- Anonymous1 decade agoFavourite answer
i agree with jay about the elevation angle..... i hope what i have solved below is right:
since from the point on the street both angles are 45 degrees then the distance from the point to each of the building is equal to the height of the respective building as tan 45=1.let us assume that observer is at a distance x from building 1 and y from building 2. hence height of building1=x and that of building2=y.
when the observer moves 21 feet toward 1st building(say) then distance from building1= x-21 and from building2=x+21. elevation angles will be 65degrees and 25 degrees respectively. since height of buildings are x and y as deduced above.....
tan 65= x/(x-21)
2.1445=x/(x-21)
2.1445x - 45=x
x=39.349
similarly
tan 25=y/(y+21)
0.4663=y/(y+21)
0.4663y + 9.792=y
y=6.678
therefore height of building1= 39.349 and height of building2= 6.678
- 1 decade ago
You can solve this by using tan = opposite/adjacent.
However, I have one question before I answer your question; if an observer moves 21 feet closer to a building, the angle of elevation would increase not decrease. Am I confused by the wording?
Source(s): None.
