Angle of Elevation

esmilitar's picture

Please help to solve this problem:
The angle of elevation of a point C from a point B is 29042'; the angle of elevation of C from another point A 31.2 m directly below B is 59023'. How high is C from the horizontal line through A?

Jhun Vert's picture

$\alpha = 90^\circ - 59^\circ 23' = 30^\circ 37'$

$\beta = 90^\circ + 29^\circ 42' = 119^\circ 42'$

$\theta = 180^\circ - \alpha - \beta = 29^\circ 41'$



$\dfrac{x}{\sin \beta} = \dfrac{31.2}{\sin \theta}$

$x = 54.73 ~ \text{m}$

$y = x \sin 59^\circ 23'$

$y = 47.098 ~ \text{m}$       answer

esmilitar's picture

Thanks a lot sir its a great help.

esmilitar's picture

Thanks a lot sir its a great help. I had another solution using tangent got the same answer..

esmilitar's picture


A'C=y=31.2 + y'
y=31.2 + y'

tan 29042'=y'/x

x = y'/ tan 29042'
tan 59023'=y/x
tan 59023'=(31.2+y')/(y'/(tan 29042')
(tan 59023')(y')/(tan29042')=31.2 +y'
y=31.2 + 15.898
y=47.098m Ans

Jhun Vert's picture

Yes. also an straightforward solution.

Add new comment

Deafult Input

  • Allowed HTML tags: <img> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <sub> <sup> <blockquote> <ins> <del> <div>
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
  • Mathematics inside the configured delimiters is rendered by MathJax. The default math delimiters are $$...$$ and \[...\] for displayed mathematics, and $...$ and \(...\) for in-line mathematics.

Plain text

  • No HTML tags allowed.
  • Lines and paragraphs break automatically.
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.