instruction: Given this paragraph, how big are the non-volley zones in pickleball and where are they located?
context: The appearance of a pickleball court, and the manner of play, resembles tennis, but the court is the size of a doubles badminton court, less than a third the size of a tennis court. Court lines and rules are specific to pickleball and include two 7-foot areas (2.1 m) on either side of the net known as the non-volley zones, where the ball cannot be hit with the paddle unless the ball bounces first. The official rules specify side-out scoring, where only the serving team can score a point. All serves are made with an underhand stroke. The hard plastic ball used in pickleball produces significantly less bounce than softer flexible balls, such as a tennis ball. The minimal bounce combined with the non-volley zone and underhand serve give the game dynamic pace and strategy ranging from soft dink shots that stay within the two non-volley zones to powerful drive shots and overhead smash shots. To minimize any advantage the serving or receiving side might have at the beginning of the game, the ball must bounce once on each side of the net before either team may volley the ball, which is to hit the ball in the air before it bounces.
response: 7-foot areas on either side of the net known