This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
The cup is readily made of a piece of paper 8 in. square. Lay the paper on a flat surface, turn the point A over to meet the point B and crease on the dotted line CD, Fig. 1, then turn the corner D up to meet the line BC, Fig. 2, making sure that the new edge DE is parallel with the lower edge and crease. Turn the corner C in the same manner, that is, fold it over to the point E and crease. Fold the two corners at B outward and down, and crease, and the cup is complete as shown in Fig. 3. - Contributed by W. Douglas Matthews, Chappaqua, New York.
Ill: Fig.3 Several Cups can be Nested Together and Carried in the Pocket or Hand Bag