Solve the last triple of the first two layers. Two approaches are provided, one is intuitive and the other is algorithmic. The intuitive version is great for new users who want to start solving immediately. Then once comfortable with the intuitive version, the algorithmic version provides a lower move count and higher TPS due to the speed optimal solutions.
The last triple can also be solved completely intuitively by following a process similar to 3x3 F2L corner and edge pairing. The corner can be paired with a triangle then inserted.
Before starting, try using any combination of F' U F, F' U' F, BR U BR', and BR U' BR'. Notice that it works just like the last slot on 3x3. Each of them move around the bottom triple and three U layer triples. The big U layer center stays in place. These simple motions are used to solve the bottom triple.
Start by finding the corner that belongs on the bottom layer. Check where its orange sticker is located. Then check if an orange triangle is on the opposite side.
1. Find the bottom layer corner then check where its orange sticker is located based on its orientation. The corner is on the U layer at the back right in the image. The orange sticker is on the back.
2. Next, ensure that an orange triangle is in pairing position on the opposite layer. The triangle is on the U layer at LF in the image.
3. Turn the R layer to pair the corner with the triangle. In the image, R' was used.
4. Move the pair to the correct side of the group of three B center pieces that are now on the U layer. Use simple separation moves to move the pair - F' U F, F' U' F, BR U BR', or BR U' BR'. In the image, F' U F was used.
5. Move the pair and center group over to the R layer and solve. The bottom triangle will be solved next.
If an orange triangle isn't in pairing position at the start of the step, position an orange triangle using F' U F, F' U' F, BR U BR', or BR U' BR'. To keep the corner on the upper layer and in its current orientation, if the corner is at the upper front, use F' U F, F' U' F, BR U BR' U', or U BR U' BR'. If the corner is at the upper right, use F' U F, F' U' F, U BR U BR' U, or U' BR U' BR' U'.
1. Find the bottom triangle. In the image, the triangle is at the LF position on the U layer.
2. Turn the R layer and move the pair and center group out of the way.
3. Move the triangle over into position to be solved. The triangle is on the left side of the corner that it is currently attached to, so BR U BR' or BR U' BR' will be used to solve the triangle.
4. Use the same separation moves to solve the bottom layer triangle without affecting the pair and center block. In the image, BR U BR' was used.
5. With the triangle solved, position the pair and center block and solve with R or R'. In the image, U R finished the first two layers.
If the DR corner is already paired with a triangle at the beginning of Part 1, the basic option is to pair with a new triangle. But there is a better way. First, solve the pair correctly in the F2L using one of the separation moves. Then, solve the bottom triangle using an adjustment of the R layer and one of the four separation moves.
Solving the two triangles can be a merged process. Solving the bottom layer triangle in Part 2 will always start with an R or R' move. This provides the opportunity to keep the initial pair and center block on the upper layer and make use of the freedom to solve the second triangle. The pair and center block can be solved to the last layer at the very end.
As an example, continue from step 4 of Part 1: First Triangle.
4. Instead of solving the pair and center block, locate the bottom triangle. It is at the BL position.
5. Use the same separation moves to solve the bottom layer triangle without affecting the pair and center block. In the image, BR U BR' was used.
6. With the triangle solved, position the pair and center block and solve with R or R'. In the image, U R finished the first two layers.
The first part of solving the last triple is to place the corner. This is a simple insert using either F' U F or BR U' BR'. Check the orientation of the corner then insert using the appropriate algorithm. If the corner is in its correct location but misoriented, use either of the two algorithms to bring it to the upper layer, then correctly solve the corner.
F' U F
BR U' BR'
Next, the bottom triangle will be solved. This involves using three simple algorithms that move the corner that was just solved out of the way, places the triangle, then restores the corner. Do a slight horizontal rotation to have the right side layer in front and the algorithms can be executed similar to F U R U' R' F', F R U R' U' F', and F r U R' U' R r' F'.
R U BR U' BR' R'
U' R BR U BR' U' R'
R br U BR' U' BR br' R'
The last step to solving the triple is to place a right side triangle above the corner. There are three to choose from so they will be easy to spot. Use the correct algorithm depending on if the triangle is to the left or right of an edge on the upper layer.
U' BR R BR' U BR U' R' BR'
U F' R' r U' r' F R F
Once accustomed to the starter steps, the first two parts of solving the triple can be combined. The corner and bottom triangle can be simultaneously solved using one of 23 algorithms. Go to the document below for the complete algorithm list.
The most advanced version of solving the triple is to solve the three pieces all at once. The full set can be learned from the following algorithm document.
To reduce the number of cases for the last triple, it can be ensured that the corner isn't placed in its slot before arriving at the step. At the end of solving the centers, solve the centers in a slightly different way to keep the last triple corner on the upper layer. If the corner is attached to the end of the half center and would be placed in slot with the R U' R' or R U R' ending, the corner can be moved out of the way. Below are the two main alternate endings to prevent the corner from being placed in its slot.
R F' U' F R'
R BR U BR' R'