Radians are really important to use in trig because they they are much more simple to work with, rather than working with degrees. When you have radians you are only dealing with pie which can be worked in and out with any type of equation. Where as if you use degrees you are going to have to graph it figure out where the equation is located on the graph and then convert to radians.

When working with theta you ALWAYS want your answer to be in radians. When you are given theta in degrees it is very simple to convert into radians, you and going to multiply by pie over 180 degrees. This will cancel out the degrees leaving you with a faction most of the time and occasionally a whole with pie in the numerator part of the fraction or when dealing with a whole number pie will be right next to the number as if the number were being multiplied by pie.

Examples:

1. (theta)=150(degrees)
150x (pie)/ 180
=5(pie)/6

2. (theta)=270(degrees)
270x(pie)/ 180
=3(pie)/2

3. (theta)=360(degrees)
360x(pie)/ 180
=2(pie)