# Horizontal Angle/Circle

## Homework Statement

I have been told to work out the Horizontal Angle when given the Horizontal reading of face left and face right at different sights. For example:

Face Left---------Face Right

A - 26 12 48--------206 12 59
C - 172 23 08--------352 23 17

I am unsure how to work out the Horizontal Angle from here. I know 172 - 26 = 146 is correct but when I attempt the likes of 8-48 = 40, it comes up wrong.

Any help on this please?

## Answers and Replies

mgb_phys
Science Advisor
Homework Helper
You are supposed to subtract each face left from face right.
If you did it right you shoudl get the same answer for each set of measurements

As silly as this may sound, how would this be done on a calculator using the numbers given? Thanks so much.

mgb_phys
Science Advisor
Homework Helper
if you have a caluclator with a dms button use that, otherwise simply convert into decimal degrees and then convert back at the end.
eg. 26 12 48 = 26 + 12/60 + 48/(60*60) = 26.2133

Be carefull of readings where you go over 0/360. ie left =359, right=1 is a difference of 2