Please help! with my math

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

Use the net as an aid to compute the surface area of the triangular prism. a) 550 m2 b) 614 m2 c) 670 m2 d) 790 m2

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.