Anyone know how to solve this?

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°?

What is the effect on the graph of the function f(x)=x when f(x) is replaced with -f(x)+4

The measures of the legs of a right triangle are 15m and 20m . what is the length of the hypotenuse