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Puzzle #9: Move 2 Planks to Make 5 Equilateral Triangles

wooden plank puzzle 9

Here's another puzzle for the geometric geniuses of Brain Blox Nation.  Can you turn these 3 equilateral triangles into 5 equilateral triangles by moving only 2 planks?

If you're wondering what an "equilateral" triangle is, it's simply a type of triangle in which all three sides are equal.

Build the Puzzle First

Brain teasers like this are more fun if you build them yourself on a table so you can test your ideas.  So grab 9 Brain Blox (or anything with a similar shape, like markers or unsharpened pencils) and arrange them so they look like the puzzle photo above.


Now see if you can solve the puzzle!  Is this one hard or easy?

Want a Hint?

Don't read any further unless you want some help solving this puzzle!

Hint #1: The 5 triangles will not all be the same size.

Hint #2: The solution will have 1 large triangle, and 4 smaller triangles inside the larger one.

Hint #3: Try moving the 2 planks that are sticking out on the bottom right.


Ready for the solution?  Here you go! 

wood plank solution 9

Share Your Ideas! 

Why don't you try making your own brain puzzle now?

Take some wooden planks and lay them out on a table.  Make some shapes, then move parts of it around to see if you can come up with a fun challenge of your own.

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