Image down below thx

When you are making a circle graph by hand, how do you convert a number for a part into its corresponding angle measure in the circle graph? when you are making a circle graph by hand, what should you do if one of your angle measures is greater than 180°?

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

What is the area of the shaded sector?