SOLUTION: A man measures the angle of elevation to the top of a mountain to be 12 degrees. He drives 7 miles closer and finds the angle of elevation to be 37 degrees. How high is the mountai

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A man measures the angle of elevation to the top of a mountain to be 12 degrees. He drives 7 miles closer and finds the angle of elevation to be 37 degrees. How high is the mountai      Log On


   



Question 1034720: A man measures the angle of elevation to the top of a mountain to be 12 degrees. He drives 7 miles closer and finds the angle of elevation to be 37 degrees. How high is the mountain?
Found 2 solutions by addingup, MathTherapy:
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
Use the tan function on both angles, and solve the equation, but first convert miles to feet:
7 miles = 36960 (1 mile = 5280 feet)
height/(length+36960)= tan 12
height/length = tan 37
height/(length+36960)= 0.21256
height/length = 0.7536
Height of the mountain:
h= (36960*0.7536*0.21256)/(0.7536-0.21256) = 10942.71 feet
Hopefully I have it right. Please let me know if I don't. Learning is a continuous cycle.
John

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
A man measures the angle of elevation to the top of a mountain to be 12 degrees. He drives 7 miles closer and finds the angle of elevation to be 37 degrees. How high is the mountain?
With y being the distance from where he walked to, to the base of the building, the following proportion can be set up:
%287+%2B+y%29+%2A+tan+%2812%5Eo%29+=+y+%2A+tan+%2837%5Eo%29
%287+%2B+y%29%2Fy+=+tan+%2837%5Eo%29%2Ftan+%2812%5Eo%29
%287+%2B+y%29%2Fy+=+3.545193
3.545193y = 7 + y -------- Cross-multiplying
3.545193y – y = 7
2.545193y = 7
y+=+7%2F2.545193, or 2.750283
Now, height of mountain = matrix%281%2C3%2C+y+%2A+tan+%2837%5Eo%29%2C+or%2C+2.750283+%2A+tan+%2837%5Eo%29%29 = highlight_green%28matrix%281%2C2%2C+2.072487%2C+miles%29%29
If familiar with the Law of Sines, you can also use this to find the height. As a matter of fact, this method is easier.