4 replies to this topic

[Benson]

How to use a scissors to cut any 1 rectangle shape of paper 2 times and get no more or less 5 triangles?

Spoiler for solution

1.Fold the rectangle to two same size rectangle
2.Cut it diagonal and get 3 triangles
3.Put the same size triangles together and cut from one angle to the opposite side

[bonanova]

Do the cuts have to be straight lines?

[Benson]

Do the cuts have to be straight lines?

Yes.

[bonanova]

For the cut-pieces of a rectangle to form triangles, the cuts must pass thru corners [not sides].
Only two such cuts exist - along the two diagonals.
That gives you 4 triangles, not 5.

The only other way to cut a rectangle is to cut it after it has been folded.

All my tries at this so far have led to an even number of triangles.
I'll keep trying.

[Benson]

For the cut-pieces of a rectangle to form triangles, the cuts must pass thru corners [not sides].
Only two such cuts exist - along the two diagonals.
That gives you 4 triangles, not 5.

The only other way to cut a rectangle is to cut it after it has been folded.

that's the trap.

Spoiler for hint

You need to fold the paper.