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How to build the Soma cube arch

The arch uses all seven Soma pieces, 27 cubes in total. Here is one solution: first the finished figure, then the pieces one by one from the floor up, in an order you can follow with real pieces.

LAVPZBT
The finished arch, seen from the front left and above: the front is at the lower right, the left side at the lower left.
  • Vsmall corner
  • LL shape
  • TT shape
  • Zstep (Z shape)
  • Atwist A
  • Btwist B
  • Pbranch

Open in 3D, piece by piece

Opens the solver with this figure. Press "Next" to place one piece at a time, and drag to turn the view.

Step by step

Build in this order from the floor up, lowering each piece from above. Every piece rests on the floor or on pieces already placed.

  1. L

    Step 1 · Place piece L (L shape) on layers 1–2, on the right. It stands upright like a wall running from front to back.

  2. A

    Step 2 · Place piece A (twist A) on layers 1–2, at the back left. Two of its cubes are on layer 1 and two on layer 2.

  3. V

    Step 3 · Place piece V (small corner) on layers 1–2, at the front left. It stands upright like a wall running from left to right.

  4. P

    Step 4 · Place piece P (branch) on layers 2–3, at the front right. Three of its cubes lie on layer 2, and one sticks up onto layer 3.

  5. Z

    Step 5 · Place piece Z (step) on layers 2–3, at the back right. It stands upright like a wall running from left to right.

  6. B

    Step 6 · Place piece B (twist B) on layers 2–3, at the back left. Two of its cubes are on layer 2 and two on layer 3.

  7. T

    Step 7 · Place piece T (T shape) on layer 3, at the front. It lies flat: a row of three from left to right, with the fourth cube sticking out to the back from the middle. All 7 pieces are in place and the figure is finished.

Layer by layer, seen from above

Layer 1 is the floor. In each plan the top edge is the back of the figure and the bottom edge is the front.

VLALAL
layer 1 · floor
VVPLBBPPAAZZ
layer 2
TTTBTPBZZ
layer 3

About this figure

Open in 3D, piece by piece