Change  to degrees:



We subtract 360° enough times to get a
a positive coterminal angle less than 360°: 

660°-360° = 300° (it was only necessary to
subtract 360° one time.)



That is in QIV, So to get the reference
angle, we subtract from 360° and get 
360°-300° = 60°.

The secant, which is the reciprocal
of the cosine, and the cosine is +
in QIV, so 



Edwin