Answer:
I would say 120 but that could be also be wrong but ill go with 120
Answer: 3.5% with a 3.50 Tip
Reason: 25.00 - 21.50 = 3.50
The opposite angles of a quadrilateral are supplementary so you can set them equal to 180.
If there was more information given then i could find the exact values.
Hope this helps :)