High school mathematics, how to imagine three-dimensional with three kinds of vision? I only remember that the teacher said that from the bottom, if you are worse than me, you can look more. I can't even do simple things. You can draw a positive (long) cube first, then dash the line on the cube according to the three views, that is, start from the bottom, and then pull up the line according to the hit point, and you can almost draw it. That's how I used to draw. This is more effective. Draw a few more times and you'll find the feeling