paste this into a google search window:
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(acos(cos(pi*(135.8+77.9)/180)*sin(pi*49.2/180)*sin(27.6*pi/180) + cos(49.2*pi/180)*cos(27.6*pi/180)) ) ) in degrees

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Note that this is a great way to carry out calculations for this course. You can check your answers and copy/paste your work directly into your document for submission.  

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Still having trouble? Did you try copy/paste into a web browser search window? <br>
If so, did you remember to copy the whole thing, including the 'in degrees' ? Otherwise, you'll get an answer in radians.