LATEST - Symmetric Shape Puzzles From IPP37

Three of around half dozen symmetric shape puzzles featured. Puzzles from Nick Baxter, Tomas Linden/Vesa Timonen and Emrehan Halici. Please follow the link below.

http://mechanical-puzzles.com/symmetric-shape-puzzles/

3 Pentagons

This past weekend, I played with Japanese puzzler/designer Koshi Arai's 3 Pentagons. The object of the puzzle is to lay the pentagon shaped (5 sided) pieces on a flat surface and form a symmetric shape. 

For this puzzle, there were not one but three solutions and Koshi had in fact (generously) shown one of the symmetric shape solutions on the instructions that came with the puzzle. The task is figuring out the remaining two. 

This is the 1st symmetrical shape solution provided by Koahi Arai

3 Pentagons was not only Koshi's IPP34 Exchange Puzzle but he also entered it for the Puzzle Design competition. His exchange version is finely made of an exotic (dark) wood (cocobolo?) and all the pieces precisely cut. 

Unless you know the meaning of "symmetrical shape", you won't even know where to begin. There are typically two types of symmetrical shapes possible, one is mirror or line symmetry and the other is rotational symmetry. In most (if not all) of these symmetrical shape type puzzles, usually the object is to find a mirror/line symmetrical shape, which is the case here.

It took me several sessions over two days to find the two solutions. What makes the puzzle so difficult is that the three pieces are pretty similar in shape (and size) to each other and this sets up a huge number of possible combinations for joining the pieces side to side; yet only three symmetrical shapes exist. What an incredible design! I am very sure there is some complicated mathematics to all this but sorry folks, I am not capable of explaining any of it here...all I know is that I tried all sorts of ways to put the pieces together and eventually got the results I wanted.

Overall a very challenging puzzle indeed and a good thing that Koshi revealed one solution at least! If anyone wants to know the other two solution shapes, please contact me via my blog email.

Of Symmetry And Shapes

This weekend's puzzle play consisted of Symmetrick from Vesa Timonen of Finland and Four Triangles Five Shapes from Emrehan Halici of Turkey. 

Symmetrick

Symmetrick was a Top 10 Vote Getter during the IPP33 Puzzle Design Competition in Japan. It was also Vesa's exchange puzzle during IPP32 the previous year. In case you didn't know, vesa is a very prolific designer with a number of Hanayama Cast puzzle designs to his name.

Comprising of just two irregular shaped pieces made of Finnish Curly Birch wood in a raw finish, the goal here is to form a symmetrical shape. The instructions are clear....to place the two pieces on a flat surface to form a symmetrical shape...no tricks, no silhouette, hole in centre and the like.

One would wonder how difficult can that be with just two pieces right? Wrong...it is in fact a rather difficult puzzle, more so if you don't even understand what a symmetrical shape refers to. 

During IPP33 itself, I had already seen quite a number of puzzlers in the competition room trying to figure this one out.... and many couldn't solve it even by the end of the event. All round it received a lot of positive comments. I took about a couple of hours before hitting the jackpot. Please PM me if you would like to see the solution...it's really quite unexpected.

Symmetrick IMHO is really an example of a great puzzle design, so simple and innocuous looking with just two pieces, yet very challenging. For those who love this sort of shape forming puzzles, its a must have. Available from Mr Puzzle Of Australia and Sloyd of Finland.

Four Triangles Five Shapes

This puzzle came courtesy of Emrehan Halici. I had a privilege of meeting Emrehan the second time during IPP35 in Ottawa last year and his Four Triangles Five Shapes (FTFS) was his exchange puzzle to me.

The FTFS is made of 3mm red laser cut acrylic. The four pieces comprise of four triangles of different shapes. Nicely cut and pretty large pieces so easy to handle.

There are five different tasks here (hence the name "five shapes"). Using all the triangles to make the following shapes:-

1. 3 different Pararellograms

2. An Isoceles triangle

3. A Square

I was able to make just one of the parallelograms, the isoceles triangle and the square...or so I thought. I shot an email to Emrehan for the solutions to the other two parallelograms and when he replied I was in for a shock; I had only gotten the square correct!

How difficult is the FTFS? Well, I only managed to solve one of the five shapes, despite just four pieces. I would rate it as very challenging indeed. As this one is an exchange puzzle, it's only available from the designer (assuming he has any left), so please PM me if you would like to get a copy and I will link you up with Emrehan.

Supersymmetry

Here's another put-together puzzle that I got nowhere with. Supersymmetry is Stewart Coffin's #247 design and was Tom Rodger's IPP30 exchange puzzle in Osaka, Japan in 2010.

I saw the Supersymmetry during one of Nick Baxter's puzzle auctions and there were around seven copies available for sale. It looked really cool (and had such a cool name too!) being made of walnut, with its own plastic container and "appeared" quite do-able for me. After all, there are only 6 pieces and they didn't look like complicated burr pieces with multiple notches and grooves, so how tough could it be right? wrong, I should have know better that a Coffin puzzle would not be easy. So I went for it and made sure I won a copy.

Looks symmetrical, but is not and can't fit into the container

Well, when it arrived a couple of weeks later, I had problems from day one. While only 6 pieces consisting of equal length rods, the notches were cut diagonally. The object was to form a symmetrical shape and there were 8 solutions for this. I would have been happy to just find one solution, never mind it didn't fit into the plastic container. But unfortunately, I could not even get the rods to interlock together to form any sort of shape at all!

Burr Tools of course was no help for puzzles like these. But I happen to know that fellow puzzler and collector, Oli Sovary-Soos had a copy of the same puzzle (and Oli is quite a super-solver). So I promptly shot him a message for help. He very kindly responded with photos of the solved Supersymmetry from different angles. After quite a good number of days of on-and-off trying, I still got nowhere and asked if he had a step by step solution. The orientation of the rods and how they interlocked I just couldn't figure out from the photos. He sent a second round of photos, this time one photo showed a partial dis-assembly. With this I managed to get an interlocking puzzle, but still not a symmetrical one. Finally after several more tries, I got the right solution; which slipped nicely into the container.

Very difficult, even looking at photos. Trying to get the pieces just to come together properly (without force) is very hard in itself (and even Oli says he doesn't dare to fully take apart his copy). I doubt I will be removing and disentangling the pieces anytime soon, just happy to leave it in its container.