Help With Hole Punching Question

[Kittenz]

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I've been trying to remember the rules for LOS, and I'm specifically stuck on this. If I remember correctly, all half hole punches are treated like full hole punches. Also, holes on the line of symmetry do not get folded over, or removed. Holes that already exist can be erased if another hole folds on top of it. Can someone correct me where I'm wrong? I've done an example that causes me to get the wrong (but close) answer following these rules. The thick gold lines represent the LOS, the red circle represents it being folded on top of, the skewed lines represent holes folding over the LOS to their mirror image.

 

[KyoPhan]

Erase the red circle in the 4th picture. Then you will fold to get the red circle back in the 5th final picture.

No 6th picture needed.

 

[Kittenz]

What gets rid of the red circle in picture 4? I don't see any holes folding on top of it while trying to follow the LOS rules. I understand what happens without trying to follow the rules, but I'm just trying to understand what in the LOS technique would erase the red circle before the 4th picture, so that I may apply the technique/rules on future problems.

 

[KyoPhan]

I don't remember all of the rules listed. But going from picture 3 to 4, when it folds over, the red circle's space becomes empty. That's why we use the erase rule.

 

[Kittenz]

I had great help with my last question, but I've got a new question. The correct answer is D, but I keep getting step 5 following the LOS rules as well as I can remember them. I must be making a mistake somewhere. The Light Green lines I've used to indicate the LOS where the circles will be reflected, the Orange lines I've used as boundaries for the shape being reflected, blue lines I've used to show where the circles fold to, the red cross through the circle in #2 indicate that the circle is no longer on the shape, and the filled in Red circle shows that a circle has gotten folded on top of by another circle (making it go away). Thanks!

 

[AliceF]

Where are you guys getting such good grids from?

 

[KyoPhan]

Don't erase the red hole at step 4. If you look at the problem before, we erased the circle because a gap was formed where the circle was.

In the new problem, for step 2, you erased because the gap was formed at the bottom left part of the grid. In step 4, we have to realize that the paper above, and the paper below are both punched at the top right of the right triangle you drew. So going to step 5, the red circle remains, and a new circle is formed at the bottom left.

 

[Kittenz]

That makes sense, I just couldnt get to the answer following the LOS rules, this must be an exception to the folding over another circle rule, or I'm skipping a step entirely somewhere because I would have thought that folding on top of another circle always makes it go away.