A stroke of four strokes and nine dots of the line can not intersect trouble to help

Number the nine dots 1-9

123 into a straight line.

147 into a straight line.

159 into a straight line.

68 into a straight line.

Just draw the composition of the figure in one stroke.

Start by setting the nine points. The top is the middle, and the bottom is.

Let's start drawing. Start with 1. After 5 to 9

This is the first line, and then it starts at 9. Scripture 6 to 3And extend it out.

This is the second line, then. By extending the position from 3 to 2 to 4The same extends out.

This is the third line, the last. The position extended from 4 intersects with 9 by 7 over 8. This is the last line.

Actually, it's an isosceles triangle. Try to draw as long as possible. Draw twice and you'll be able to grasp the pattern.

If I'm not mistaken, this is a question in "The Adventures of the Sloppy King" that I watched when I was a child, and the two upstairs are actually drawn in the same way, but the angle is different.

But I don't understand, what does the landlord mean when he says that lines and lines can't intersect? Aren't disjoint lines parallel lines? So how can you draw it with a single stroke?

There are three in the first row, which are 11, 12, 13, in the same way, the second row and the third row are 21, 22, 23, 31, 32, 33, the first row and stick out the head, the second row and stick out the head to the position of the first column, the third row and the fourth row.

The Adventures of the Sloppy King" is there! It's a combination lock that you can open after being stained with mold!

Yes, as shown in the image below:

One-stroke question:

Geometry in the traditional sense is the study of the shape, size and other properties of the figure, and there are some geometric problems, the object they study has nothing to do with the shape of the figure and the length of the line segments, but only the number of line segments and the connection between them, such as the one-stroke problem.

That is, can a figure composed of curved segments on a plane be drawn in one stroke so that it is not repeated on each line segment?

For example, the Chinese characters "日" and "中" can be drawn in one stroke, while "田" and "目" cannot.

The two connected areas can be drawn with one stroke, for example, the two connected areas of the plane 4 areas can be drawn with one stroke; 7 areas connected by pairs on the tire shape can be painted with one stroke; We can construct an infinite number of connected areas in a multidimensional space.

Connect the nine dots.

Haven't you watched "The Adventures of the Sloppy King"???

Personal opinion only.

I'd better go to the corner and draw a circle...