Bricks Activity 

Student Page

Teacher Lesson Plan

Use Matt Wringe's applet, Bricks Activity, to think about this problem.

The problem:

You are a brick wall builder in Southern California. You have discovered how to build the strongest wall possible using 2-by-1 bricks. You have come to the conclusion that a wall made of these bricks has the most strength if there are no fault lines. Here is an example of a brick wall with a fault line. You can see that there are lines that go through the wall uninterrupted.

You have found a masonry pattern without any fault lines. This means that every grid line (that is, the lines, both horizontal and vertical, spaced at the width of one domino and extending perpendicularly between parallel edges) of the rectangle intersects at least one domino.

You found this special masonry pattern by considering first one brick, then two bricks and you continued until you found a fault free pattern.

Consider two bricks:

In case 1) the fault line is vertical. In case 2) the fault line is horizontal.

Consider three bricks:

In all three cases the fault lines are vertical.

Continue the investigation using more bricks:

Do you have a system for your investigation?
Once you find a fault-free pattern, draw it.
Describe how you found your pattern.
Are there other fault-free patterns using this number of bricks or is the one you found unique?

Do you need a hint?

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