Can you join all nine dots with four straight lines without taking your pencil off the paper?

Can you join all nine dots with four straight lines without taking your pencil off the paper?

Your task is to join all nine dots using only four (or less) straight lines, without lifting your pencil from the paper and without retracing the lines. Yet another solution is to fold the paper in three, so the rows of dots all line up, and fold it again and poke the pencil through!

Can you draw four straight lines without lifting your 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.

Can you connect the nine dots with just 4 straight lines?

The 9 Dots Problem 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.

What is the minimum number of straight lines to connect all the dots on this grid?

If so, what about 10? Just to be clear, you have to draw 11 lines that meet all dots.