Prism 棱柱 2.Getting points on the surface of a prism棱柱表面上取点 Method Getting points on surfaces of a prism can be based on the accumulation 方法： characteristics of edge lines or plane projection. 棱柱表面上的点可利角棱线或棱面的积聚性投影求之。 The projection of point is also visible when it is on visible edge or plane. ldentification 凡在可见表面及棱线上的点，其投影为可见： 判别： The projection of point is not visible when it is on invisible edge or plane. 凡在不可见表面及棱线上的点，其投影则为不可见。 Labeling All invisible points are written in brackets. 击 标注 对不可见的点加括号以示区别。 Example1.Draw the triangular prism and get points on the surface. 标左 画三棱柱及表面上各点的三视图。 显 Example2.Draw the square prism and get points on the surface. 示 画四棱柱及表面上各点的三视图。 面 Example3.Draw the pentagonal prism and get points on the surface. 画五棱柱及表面上各点的三视图。4 Example3. Draw the pentagonal prism and get points on the surface. 画五棱柱及表面上各点的三视图。 The projection of point is not visible when it is on invisible edge or plane. 凡在不可见表面及棱线上的点,其投影则为不可见。 Identification 判别: The projection of point is also visible when it is on visible edge or plane. 凡在可见表面及棱线上的点,其投影为可见; Method 方法: Getting points on surfaces of a prism can be based on the accumulation characteristics of edge lines or plane projection. 棱柱表面上的点可利用棱线或棱面的积聚性投影求之。 2.Getting points on the surface of a prism 棱柱表面上取点 Labeling 标注: All invisible points are written in brackets. 对不可见的点加括号以示区别。 请 点 击 鼠 标 左 键 显 示 后 面 内 容 Example1. Draw the triangular prism and get points on the surface. 画三棱柱及表面上各点的三视图。 Example2. Draw the square prism and get points on the surface. 画四棱柱及表面上各点的三视图。 Prism 棱柱