How meany rows should you make in an array

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.

On the day a coffee shop first opened, it had 140 customers. 65% of the customers ordered a large coffee. how many customers ordered a large coffee? enter your answer in the box.

Atruck can be rented from company a $50 a day plus $0.60 per mile. company b charges $20 a day plus $0.80 per mile to rent the same truck. find the number of miles in a day at which the rental costs for company a and company b are the same