Paper cup

Paper cup

Material needed: one square sheet of paper.

Method:

Fold the square into half to make a triangle.

now, bring the pointed end of the triangle inside and fold it while aligning it with the edge. 

Now open the fold and take one arm of the triangle and fold it in such a way that it touches the point created by the fold you had created previously.

Fold the other arm as well. 

Now fold each of the top triangular pieces in such a way that one is folded forward and one backward.

Your cup is ready. You can invert it and it becomes a cap too.