What is the distance between (–13, 9) and (11, 2) on a coordinate grid?

Could someone me with this question i’ve been stuck on it for 20 minutes

Acafeteria manager can choose from among six side dishes for the lunch menu: applesauce, broccoli, corn, dumplings, egg rolls, or french fries. he used a computer program to randomly select three dishes for monday's lunch. what is the theoretical probability the applesauce and broccoli will both be offered monday?

The weekly amount spent by a company for travel has an approximately normal distribution with mean = $550 and standard deviation = $40. a) what is the probability that the actual weekly expense will exceed $570 for more than 20 weeks during the next year? (note: one year = 52 weeks) b) what is the probability that actual weekly expenses exceed $580 for 10 or more, but 16 or fewer weeks during the next year?