7. Given five points in a plane, where no two lines connecting any two points are parallel, perpendicular, or coincident, draw perpendiculars from one of the points to the lines connecting the other points. How many intersection points can these perpendiculars have, excluding the original five points, at most?
保留源文本的换行和格式,所以翻译结果如下:
7. Given five points in a plane, where no two lines connecting any two points are parallel, perpendicular, or coincident, draw perpendiculars from one of the points to the lines connecting the other points. How many intersection points can these perpendiculars have, excluding the original five points, at most?