The Pyraminx also known as the triangle Rubik’s Cube is a tetrahedron-shaped 3-layered twisty puzzle, having four triangular faces which are all divided into nine identical smaller triangles. It is the second best selling toy in the World with 100 million pieces sold.
It was invented by Uwe Mèffert (Germany) in 1971 but it was patented after the Rubik’s Cube became famous in 1981. Meffert invented several other famous puzzles like the Megaminx, Skewb, Skewb Diamond, Teraminx, Dogic (icosahedron-shaped puzzle), and the list goes on. Other inventors were inspired by the 4-axle mechanism, Tony Fisher used it for the Golden Cube and Golden Egg.
The first official WCA Pyraminx competition was organized in 2003. The winner was the American Andy Bellenir who solved the puzzle in 14.09 seconds.
The Pyraminx solution is much easier than the Rubik’s Cube. It has 3,732,480 possible permutations which is relatively a small number (similar to the 2x2x2 Pocket Cube), so a personal computer can easily go through all of the possible scrambles. It can be solved from any random position in less than 12 moves.
1) I marked with numbers the four corners. If you see a number turn the according corner clockwise 120o but if you see an apostrophe following the number do a counterclockwise turn.
2) The solution of the Pyraminx begins with turning all the 4 corners (A) to match the center pieces. You can notice that this is just a simple turn for each corner because the center pieces (B) are linked together. After that turn the center so their colors are matching up. Now what’s left is solving the 6 edge pieces (C).
3) solve two edges next to one corner (red-yellow and blue-yellow on the picture), then using the remaining gap (red-blue) match up all the (green) centers in the bottom. Use one of the algorithms to put the third edge to its place without messing up the bottom centers.
Left algorithm: 4 3 4′ 3′
Right algorithm: 2′ 3′ 2 3
4) Now you have to permute the last layer (green) edges. Take the puzzle so this face is on the left side and to the operations needed:
Clockwise rotation: 1′ 3 1 3′
Counterclockwise turn: 1 2′ 1′ 2
Flip tow edges: 3 1′ 3′ 1 3′ 2 3 2′