Tennis courts have a lot of lines on them, and each one means something different and the boundaries could change as well depending on how many people are playing.A tennis court is a rectangle, with lines that mark the outside boundaries of the court. These are called the sidelines and baselines. Two smaller rectangles, inside the larger rectangle, mark the service boxes. The player’s first hit (serve) must cross the net and bounce within the smaller rectangle to start the point. Boundaries for doubles (2 players against 2 other players) are called “doubles alleys”. These boundaries (or baselines) are wider than the boundaries for two singles players.
The size of the rectangular court for singles is 78 feet long and 27 feet wide. The doubles alleys add 4 and 1/2 feet to the width on each side. The service line runs parallel to the baseline and is 21 feet from the net. The service center line runs down the middle of the court from the net to the service line. This makes two equal service boxes 21 feet long and 13 and 1/2 feet wide.
The net is in the middle of the court, halfway between the two baselines. The net is 3 feet high at the center of the court. The net must be 3 and 1/2 feet high at the singles sidelines or at the doubles sidelines or alleys.
Courts, racquets and fuzzy balls 