The rules of football match are formulated and revised by international football association board (IFAB), which are the rules that regular football matches must abide by. Draw two lines perpendicular to the goal line from the inside of each goal post 16.5 meters (18 yards). These lines extend to 16.5 meters (18 yards) on the playing field and are connected with a line parallel to the goal line. The area composed of these lines and the goal line is the penalty area.
The extended information competition venues are marked with lines, which are included in each area and serve as the boundary line of each area in the venue.
The two longer boundary lines are called sideline lines and the two shorter boundary lines are called goal lines.
The width of all lines shall not exceed 12 cm (5 inches).
The playing field is divided into two halves by the center line.
Make a center mark at the midpoint of the center line of the site, and draw a circle with a radius of R=9. 15 meters (10 yards) with this point as the center.
A flat-topped flagpole of not less than 1.5 meters (5 feet) should be erected at every corner of the site, and a small flag should be hung on the flagpole.
Flagpoles can also be placed at both ends of the center line and not less than 1 m (1 yard) outside the sideline.