How can you cut out a shape of a cross from a regular piece of paper with one, straight cut? Follow the steps below to find out.
Steps
Fold the top corner down to the edge of the paper.
Fold the top right corner down.
Fold in half along a vertical line.
Fold in half vertically again.
Cut along the vertical line.
Links
Erik and Martin Demaine developed theory and techniques behind fold-and-cut figures. Erik's web site has examples of more elaborate shapes you can make.