# Tangrams

 Blog entry by Dave Owen posted 02-19-2010 04:40 PM 9371 reads 5 times favorited 2 comments

In most places (including Florida) it’s just too nippy to work in the shop, so how about taking a break! Forget the complexities of woodworking and the many other things that clutter our minds. Think instead of “fun and games” – or better still think of “wooden puzzles”.

To call a “tangram” a woodworking project would be a stretch, but for such a quick and simple project, one can provide many, many hours of fun (and occasional frustration) for kids of all ages.

For anyone who doesn’t already know, a tangram is an old Chinese dissection puzzle, thought to have originated hundreds of years ago, and possibly even earlier. Somehow I never learned about them until a few years ago, even though they are well known to many both as ‘fun’ puzzles and as teaching tools. Think of a tangram as a seven-piece ‘jig-saw-type’ puzzle with all pieces having straight edges. Their uniqueness lies in the geometry of the pieces. Because of the relationship of the angles and lengths of the sides the pieces of a tangram can be arranged not only into a perfect square – but into hundreds of other shapes as well – shapes resembling people, animals, objects, geometrics, etc. Each such shape is a puzzle in its own right. The three pictures below should give you a better idea.

One would think that any puzzle with only seven pieces would be pretty simple – but that’s not necessarily the case! An indication of that would be the several well-known names often associated with tangrams. For example, Louis Carol is reputed to have been an enthusiast, and even Napoleon is said to have had a tangram and a book of puzzles to help occupy time while in exile. I’ve seen a number of adults struggle for hours to solve the square – and others struggle for days to solve some of the more difficult shapes. Keep in mind that all seven pieces must be used – and that none can overlap. Below are pictures showing of the basic square – the first is a photo of an actual tangram, and the second is a drawing showing the geometry of the pieces.

I’ve included the geometry drawing more to illustrate the relationships of the sides and angles than for construction purposes. Note that there are only four different edge lengths among all the pieces. To draw a pattern, all you really have to do is to look at the diagram and notice that the angles are all either 45 deg or 90 deg, and that all lines start and end at corners, midway of a side, or at other easily located points. Just be sure the square is as perfect as you can make it.

If you’d like to make one, remember that you can’t simply draw it out on a block of wood and cut along the lines. If you do, no matter what type of saw is used, the kerfs will cause you to end up with a poorly fitting puzzle. You can decide how you can best cut the pieces accurately – but the basic premise is to cut out each piece independently.

A tangram can be any size, but I like a square of about 5”. At that size, the pieces are large enough to handle – but small enough for the various puzzle shapes to fit on an 11” x 14” magnetic whiteboard. I recess a small (1/4”) ceramic magnet into the back-center of each piece and cover the back with self-adhesive felt. The felt lets the pieces slide easily on the smooth surface – while the small magnet holds the pieces snugly against the board. You don’t have to have a special surface, of course. Any flat surface – or even the floor will do.

I’ve made tangrams of wood, but I usually make them of 1/2” MDF, spray painted in a bright color. (The edges of MDF will paint more evenly if they are first coated with spackling compound – then sanded smooth). If wood or plywood is used (unfinished or with a natural finish), keep in mind that the grain of the wood can either be a help or a hindrance to solving the puzzle, depending on the direction of the grain in the various pieces. I also find the grain distracting when making the various shapes.

To find out more about tangrams, or to find puzzle layouts of various figures and shapes try ‘Googling’ “tangrams” on the Internet (also try “tanagram”). Many online sites have numerous shapes for birds, animals, people, objects, geometrics, etc. Some sites even have interactive tangrams that can be solved online. The picture below shows a few of the eighty puzzles I’ve drawn for those to whom I’ve given sets. Incidentally, I’ve also drawn the solutions (or cheat sheets) for each – but I’m sure you wouldn’t be interested in those.

If anyone decides to make a tangram and has any questions, please post a message.

-- Dave O.