Maths Angle: A surveyor measures the angle of elevation as 19 degrees....

Ted_Grendy

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Hi all

I was wondering if someone could help shed light on the following maths problem.

A surveyor measures the angle of elevation of the top of a perpendicular building as 19 Degrees.
He moves 120m closer to the building and finds the angle of elevation is now 47 Degrees.
Determine the height of the building.

I can work out all the interior angles of the triangles but I cannot work out the sides of the height of the building.

Can some one help?

Thank you.
 
I was wondering if someone could help shed light on the following maths problem.
A surveyor measures the angle of elevation of the top of a perpendicular building as 19 Degrees.
He moves 120m closer to the building and finds the angle of elevation is now 47 Degrees.
Determine the height of the building.
You posted this question in the Pre-Algebra Forum. But I see no way to solve it without using trigonometry functions.
Do you know how to work with the tangent function?
 
Let x be the original distance to the building and let h be the height of the building. Initially we have an angle of 19 degrees: tan(19)= h/x. Moving 120 m closer, so that the distance to the building is x- 120, we have an angle of 47 degrees: tan(47)= h/(x- 120).

Tan(19)= 0.3443 and tan(47)= 1.0723 so we have h/x= 0.3443 which gives h= 0.3443x. That makes the second equation 1.0723= 0.3443x/(x- 120).

Can you solve for x and then h?
 
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