垂直关系是空间直线和平面位置关系的核心，是高中数学教学的重点，也是历年高考考查的热点．在各种垂直关系中两条直线的垂直是最基本的关系（以下简称“线线垂直”），由“线线垂直”可升格为“线面垂直”和“面面垂直”，从而推动着平行关系，角、距离和面积、体积等一... The vertical relationship is the core of the positional relationship between spatial lines and planes. It is the focus of high school mathematics teaching, and it is also a hot spot for the college entrance examination. The vertical relationship between two straight lines in a variety of vertical relationships is the most basic relationship (hereinafter referred to as “line vertical”), and can be promoted from “line vertical” to “vertical line surface” and “vertical surface”, thus promoting Parallel relations, angles, distances and areas, volumes, etc...