Line Perpendicular to a Plane

Field Hockey Goal

This field hockey goal has a line that is perpendicular to a plane. The backboard of the goal (yellow plane) is perpendicular to the side board of the goal (pink line) because when the two parts of the goal meet/intersect, they form a right angle. The definition of parallel lines (planes contain lines) is that when two lines intersect, they form a right angle. The structure of the goal, with the backboard as a plane and side board as a perpendicular line, follows the definition of parallel lines. These goals can be found all around the world at either field hockey fields or courts.  Field hockey players, toddlers to adults, use these goals to practice their shots and to score in games.

This picture was found online: http://www.networldaustralia.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/f/i/file_28_7.jpg