How do I do the polygon formula? And these questions

Subscriptions to a popular fashion magazine have gone down by a consistent percentage each year and can be modeled by the function y = 42,000(0.96)t. what does the value 42,000 represent in the function?

How many verticies does a triangular prims have

Of the 304 people who attended a school play, 5/8 were students. how many of the people who attended were students.