I'm trying to understand a question that I tried to do in a quiz.
The question was about Pool-
Which shape do you rack the balls in?
I guessed circle and was wrong.

Trying to figure out if I didn't understand the question or what. I thought that those pockets that the ball goes into are round?

No, it's not the pockets. The rack is the device used for making sure all the balls are placed on the table together in a proper triangle, when the balls are being set out prior to the game of pool or Snooker starting.

Here is a picture of the balls in starting position. The white (cue ball), is usually at the opposite end of the table.