Triangular Tower Prism
Java Applet Instructions

The Green Flag resets the puzzle.

Pressing the Spacebar scrambles the puzzle.

Down Arrow turns the bottom column of three triangles by 180 degrees. The
same can be achieved by clicking on the top of the upper triangle in the column.

Right Arrow turns the right column of three triangles by 180 degrees.
The same can be achieved by clicking on the top of the upper triangle
in the column.

Left Arrow turns the left column of three triangles by 180 degrees. The
same can be achieved by clicking on the top of the upper triangle in the column.

Pressing a turns the top layer by 120 degrees clockwise.
The same can be achieved by clicking on the leftmost face of this layer.

Pressing y or z turns the top layer by 120 degrees
counterclockwise. The same can be achieved by clicking on the
rightmost face of this layer.

Pressing s turns the middle layer by 120 degrees clockwise.
The same can be achieved by clicking on the leftmost face of this layer.

Pressing x turns the middle layer by 120 degrees counterclockwise.
The same can be achieved by clicking on the rightmost face of this layer.

Pressing d turns the bottom layer by 120 degrees clockwise.
The same can be achieved by clicking on the leftmost face of this layer.

Pressing c turns the bottom layer by 120 degrees counterclockwise.
The same can be achieved by clicking on the rightmost face of this layer.

Pressing q flips the entire prism over by 180 degrees
in the direction back > right. The same can be achieved by klicking
on the top of the central top triangle.

To solve the prism, you have to get the top side yellow,
the left side blue and the right side red. (The green back and the white
bottom are invisible.)

When you have solved the puzzle, your time taken is displayed
for 5 seconds.
Solution Strategy

First get one column right. This can be done intuitively
by moving the two pieces into their respective positions. For instance,
start by solving the left column: greenyellowblue on top,
greenblue in the center,
bluewhitegreen at the bottom.

Now only the six cubelets on the right are scrambled. You can exchange
two corners who are on top of each other by clicking on the top triangle of the column.

To correct all corners, we may have to exchange two horizontally neighboring corner cubelets.
For instance, to exchange the top front and the top right corners,
use F  D'  R  D  F.

Similarly, to exchange the top bottom and right bottom
cubelets, use F  U'  R  U  F.

Finally the bottom and right central cubelets may be
oriented incorrectly. Use a simple commutator such as
C'  R  C  R to correct them.

Here the notation is: F front column, R right column,
U upper layer 120 degrees clockwise,
C central layer 120 degrees clockwise,
D bottom layer 120
degrees clockwise (viewed from above), and a prime denotes counterclockwise
rotation.