Goal of Activity:

The goal of this activity is to first play around with the various configurations of sets of 4 squares and then to create a strategy for determining how many different ways that four squares can be aligned to make distinct tetrominoes. The squares must be aligned (see the “legal” and not “legal” examples.)  NOTE: if one tetromino can be rotated or flipped to match another, then the two are not distinct.

  This is a “legal” tetromino:                     These are not “legal” :

 Directions:

Pull red squares from the stack by dragging the point in the lower left corner.  Arrange them on your workspace to keep track of the designs that are distinct.  Click on the "hint" button if you need to see how to begin.  When you have completed the question, click below to check your answer.   Then, close this window and move to the next activity on the homepage menu.