That's a difficult question to answer since we really don't know what you're looking for with that question.
Let me attempt to explain though - the dish is mounted on a pole (connected at the center of the dish), and will either be moved by an actuator or an H-to-H mount. About the best movement you'll get will be 180 degrees (or half way around the pole). So from the center point (when the dish is pointed due south from your location), you have approx 1/4 of a circular turn in each direction.
As the dish turns, it will become lower towards the sides, and highest on when pointed due south. If your dish were to turn a full 180 degrees, it would actually take almost the whole 360 circle around the pole since the sides would sweep the remaining area. It will not actually take up all of the area because of the way the dish tilts, but you can figure it will take at least a cubical area 10x10x10 centered around the mounting point on the dish.