# Aluminum Foil Folds and Cut

Your task is to convert a diamond shape monomino that is made from aluminum foil into an x-shape pentomino (see figures). You may fold the monomino and make one straight cut with a pair of scissors. After the cut, you will unfold the foil and align the separate pieces. The alignment should produce the X-shape shown above, using all pieces of the original monomino. How can this be done without any additional tools?

Note: No overlapping and pieces can be flipped but not need to be attached or joined.

• Should the cut-off pieces or the remaining foil be an X after the cut? Oct 30, 2020 at 17:43
• @bobble -All the foil pieces including remaining piece or pieces
– TSLF
Oct 30, 2020 at 17:52
• How? Are the pieces placed next to each other? On top of each other? How are they attached? (This should all be added to the question as clarifications) Oct 30, 2020 at 17:55
• This earlier question brings you more than halfway to the answer, as it shows the dissection you are aiming for. Oct 30, 2020 at 19:59

A solution, and on request an asymmetric solution:

Symmetric:
Cut A=B=C=D to X after folding the blue dotted line in picture 2.
Pieces 1 to 4 are now cut off, and can be moved to make the cross.
note: The initial folds are the 1/4 - 3/4 lines
Asymmetric:
Fold A to X3, D to X1, B to X4
('line' to cut is now X1,X2,X3)
Fold X1X2 to X3X4 and then p to q
cut X4 to X3 [

• Nice.can you do without similar pieces?
– TSLF
Oct 31, 2020 at 3:19