From your measurements, you know 
, 
, and 
. You want
to determine what 
and 
are.
... first you need to use the correct angles. The ones listed
in the problem are just what was read off the protractor.
Because a reading of 
on the protractor corresponds to an elevation
angle of 
, you must subtract the angle you read off
the protractor from .
The angles should be:
Now to calculate ...
substituting for in the first equation:
Then substitute to get ...
Note this is the elevation relative to your measuring position, not
relative to sea level, as you would find on a map. Comparing this
answer to
South Sister's elevation relative to sea level though, can tell you that
you measured this data from about 1800 meters above sea level...