What is the base angles of a 9 sided polygon

How do i do this activity, is appreciated

Jamie went to home depot.she bought 25 bags of soil that cost $9 per bag.she bought 15 pots at $8 each, and she bought 23 bags of pebbles at $15 each.she used a coupon that gave her $5 off for every 100 dollars she spent. how much did jamie pay at the end?

Which of the following statements would be sufficient to prove that parallelograms pqrs is a rectangle ?