Find the number of diagonals in a polygon of n sides. how many triangles can be made​

Average acceleration: i have no idea how to do this.

Draw a tape diagram to represent each situation.for some of the situations,you need to decide what to represent with a variable andre bakes 9 pans of brownies.he donates 7 pans to the school bake sale and keeps the rest to divide equally among his class of 30 students

Madeline takes her family on a boat ride. going through york canal, she drives 6 miles in 10 minutes. later on as she crosses stover lake, she drives 30 minutes at the same average speed. which statement about the distances is true?