Please I’ll do anything I’m begging

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.

What is the maximum of the sinusoidal function

Isabelle is mixing red and blue paint to make purple paint she adds 3/10 of a fluid ounce of red to 12/25 of a fluid ounce of blue to make 1 1/30 fluid ounces of purple how many fluid ounces of red paint ounces of red paint will she need to make 3 fluid ounces of purple paint