Work out the value of n

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

The roots of the function f(x) = x2 – 2x – 3 are shown. what is the missing number?

Ihave a triangle with a 60 degree angle. lets use d for that angle. what are the values of e and f if d is 60 degrees? and what do you notice about the values of e and f?