Give a top view of the geometry, let you draw the front view and the left view, how to draw it, and what are the skills?

I'm a mechanical major. This is my experience in drawing. I hope it can help you. The question you raised is introduced in detail in mechanical drawing/engineering drawing (descriptive geometry), and you can find a textbook for reference.

Let me talk about the basic principle, which is a bit abstract, so you still need to read books and practice. Generally speaking, the horizontal dimension in the top view is equal to that in the front view. When drawing, you can drag it directly.

The vertical dimension in the top view and the horizontal dimension in the left view are also in one-to-one correspondence, which is usually realized by drawing an auxiliary straight line of 45 in engineering graphics.

in addition, unless the geometry is simple or has a three-dimensional overview. Usually, it is impossible to get the front view and the left view only from the top view. Otherwise, you don't need three views, right? Hehe.