KJV:

47 So he measured the court, an hundred cubits long, and an hundred cubits broad, foursquare; and the altar that was before the house.

NASB:

47 He measured the court, a perfect square, a hundred cubits long and a hundred cubits wide; and the altar was in front of the temple.

The size of the square in front of the Temple is 100 x 100 cubits, which is 48 x 48 meters. In order for the territory to be considered a yard, it is not necessary to enclose a solid wall, rather small posts marking its borders.