Goal (sport) the ball can be kicked either under the crossbar for a goal, or over the crossbar between the posts for a point. The vertical supports are usually called "goal posts" and the horizontal top is usually called the "crossbar". A goal in these games normally requires that the ball or puck be sent between the posts, under the crossbar and completely behind the goal line. In Australian rules football, there is no crossbar but four uprights instead. In netball, a single post at each end of the court supports a horizontal hoop that the ball must fall through. In basketball,
Five points determine a conic lines defined by opposite sides intersect in three collinear points. This can be reversed to construct the possible locations for a 6th point, given 5 existing ones. The natural generalization is to ask for what value of "k" a configuration of "k" points (in general position) in "n"-space determines a variety of degree "d" and dimension "m", which is a fundamental question in enumerative geometry. A simple case of this is for a hypersurface (a codimension 1 subvariety, the zeros of a single polynomial, the case formula_16), of which plane curves are an example. In the case of a hypersurface,