Have you understood the previous section "Drawing a line to a corner of 2"? This time I'm applying the rule further.

When two "2s" are placed diagonally as in this figure, there are some characteristics in patterns. I'll show you those patterns here. 


This is the simplest example. The following figure shows how the lines are drawn in this pattern: 


When lines are drawn in Lshape on outside edges of a vertex of diagonal "2s", that Lshape will be inherited to its diagonal edges like this figure. This pattern appears frequently in this puzzle, so it will be helpful if you are able to solve this pattern without marking "x".
Rule of diagonal "2s"  


Next, here is a case of incomming line to the diagonal corner of these "2s". 


According to the rule of "Drawing a line to a corner of 2" in previous section, the line will go out from the diagonal vertex. 


Look at the star marked vertex. If a line goes out from this vertex,
there should be an another line comming to this vertex.
It means you can use the rule of drawing a line to a corner of "2" again here. 


And eventually this line will go out from the opposite diagonal vertex. 

Rule of diagonal "2s"  

When 2s are placed diagonally, the drawing pattern will be copied among them by this rule. Once a corner is decided, other edges will be decided one after another like domino. You will feel you're lucky to find this pattern while you're a beginner, but as you get used to this puzzle, you will feel this part too easy.