在立体几何教学中,有关角的计算是一常见内容.本文介绍求线面角的几种常见方法,供同学们学习时使用.一、定义法根据斜线和平面所成角的定义:一个平面的斜线和它在这个平面内的射影的夹角叫做斜线和平面所成角,范围为θ∈(0°,90°).例1如图1,在正方体ABCD-A1B1C1D1中,求直线BC1 In the three-dimensional geometry teaching, the calculation of the relevant angle is a common content. This article introduces several common methods for finding line face angles for students to use when learning. First, the definition method defines the angle formed by slashes and planes: The angle between the slash of the plane and its projection in this plane is called the angle formed by the slanted line and the plane, and the range is θ∈ (0°, 90°). Example 1 As in Figure 1, in the cube ABCD-A1B1C1D1, find Straight line BC1