How do you connect dots without lifting the pencil?

How do you connect dots without lifting the pencil?

Your challenge is to draw four straight lines which go through the middle of all of the dots without taking the pencil off the paper. If you were using a pencil, you must start from any position and draw the lines one after the other without taking your pencil off the page.

Which figure can be drawn without lifting the pencil?

Euler's theorem says that you can only draw this shape without lifting your pen or going over the same line twice, if the number of nodes with odd degrees should be 0 or 2. In other words, there should be either NO odd nodes or exactly TWO odd nodes. If this seems arbitrary, think of it this way.

How do you draw 9 dots with 5 lines?

One classical example is where nine dots are arranged on the sides and the center of a square as in the picture below. The problem is to connect the dots with no more than 4 straight lines without lifting your hand from the paper. First attempts are always frustrating. For one always comes up with 5 lines instead of 4.