This is an angle relationship question in geometry

Ineed with number 17 i don’t get it at alll

Anyone know? will mark brainliest if you're correct!

The number if marbles of different colors stored in a hat is listed below: 4 red marbles 10 green marbles 7 blue marbles. without looking in the hat, dan takes out a marble at random. he replaces the marble and then takes out another marble from the hat. what is the probability that dan takes out a blue marble in both draws?