The other tutor did not show you how to draw the angle:

Divide 520° by 360°.

       1 
360°)520°
     360°
     160°
 
The quotient 1 is the number of complete revolutions we make
in the counterclockwise direction from the right side of the
x-axis:

The remainder 160° is the amount of rotation we must make after
we make the 1 rotation.  In the graph below, the curved spiral 
indicates the counterclockwise rotation of 520°.  

The green part of the spiral indicates the 1 revolution, and the 
red part of the spiral indicates the remainder 160°.  so 520° is
in the second quadrant. Its reference angle is the angle between 
the terminal side and the x-axis, which is 180°-160° = 20°.  

So we find the csc(20°) by first finding sin(20°)=0.3420201433 and since the
cosecant is the reciprocal of the sine, we find 

Since the sine and cosecant are positive in the 2nd quadrant, the 
answer is 2.9238044.



Edwin