Problem:

A company is investigating the most cost effective way to design the open box (a box with no top) needed to package one of their products.  Designers plan to use one of the following pentomino patterns for their box design. Pentominoes are geometric shapes formed by joining five squares edge to edge.  There are twelve unique ways to do this (not counting rotations and reflections) which are shown below.   Not all of the pentomino patterns can be folded into an open box. 

Find at least 4 pentomino patterns which can be folded into open boxes.

Answer:

These pentominoes can be folded into open boxes.

A correct answer will identify at least four of them.