Think Outside The Box Sometimes

This answer is wrong, it can be done with only 3

Solution is to literally think outside the box by drawing a line across one of the sides and extending it till another imaginary point outside the box from where we can draw a line through two more dots till another imaginary dot on the adjacent side of the square of dots. From there only two more lines are necessary to finish the job

I can do it with one big thick line that covers all nine dots at once. Nothing in the prompt says the line has to be thin or anything.

I have no solutions

Since it doesnt say you can't back track, i took it as 4 be making a E shape. Overall its still 4 lines...

you can also solve this with three lines easily!

The 4 move solution is incorrect because then you move out from the page, and that was forbidden!

You can connect all the dots using three lines, three diagonal lines would cross each point but would be sloping so that the next diagonal would cross the next three dots and then the same for the final line

We could draw them ddiagonallyand one line on other diagonal

I could even join those using just 3 lines!!!!!!!!!! theorically....join 1st three dots (kept horizontal) through a st. line take it to infinity(as st line can extend to infinity) IIIy draw line 2 & 3 through another set of 3 dot as u must be thinking u need 2 lift up your hand for that but no.......... as we know parallel line meet at infinity so if u start from 1st dot (at top extreme left in pattern) and continue to +infinity (along +ve X direction) & from there drawn a parallel line passing through 6th point continuing to point no. 4 and then moving 2 -ve infinity and from there drawn another parallel line crossing through 7th point & so on to point no 9...........Conclusion: we can join the 9 dot pattern just using 3 lines, but the ans depicted is 4 which is false as proved above

rules need to specify that you can touch any one dot more than once

Using a normal pencil sized line it can actually be done in three. Start way out side on top and cut across the top of the top left, the middle of the top middle and the bottom of the top right and extend the line past the dots and do the same thing back and back again

Fussion of (+)and (×)

In my opinion 3 will be the correct answer not 4. You can join all th three lines by making a W or M including all the 9 dots.

extend the lines beyond the given points and you will get the answer

We could get it in 3 lines, though.

1 2 3
4 5 6
7 8 9 .

1-->4-->7. From 7 (i.e., the bottom dot in the first column), you go to 2 (i.e., the top dot on the second column). From 2-->5-->8. From 8, you go to 3, then 6 and then 9.