Two planes leave the airport at the same time. in one hour the plane that has flown north has traveled 400 miles. the plane that has flown southwest has traveled 250 miles. how far apart are the planes?
law of cosines
geometry

Precalculus question, image attached.

Ahighway between points a and b has been closed for repairs. an alternative route between there two locations is to travel between a and c and then from c to b what is the value of y and what is the total distance from a to c to b?

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?