You solved the 6×10 frame.
Pentominoes are a family of geometric shapes, each formed by joining exactly 5 unit squares edge-to-edge. There are 12 unique pentomino shapes (when reflections and rotations are considered the same piece), conventionally named after letters: F, I, L, N, P, T, U, V, W, X, Y, and Z. The classic puzzle challenge is to fit all 12 pieces into a rectangular frame with no gaps and no overlaps.
Since each piece covers 5 squares and there are 12 pieces, the total area is exactly 60 squares. This means they can tile rectangles of dimensions 6×10, 5×12, 4×15, and 3×20. The 6×10 rectangle alone has 2,339 distinct solutions, making it an endlessly fascinating puzzle for spatial reasoning enthusiasts.
Select a frame size to begin. The 12 pentomino pieces appear in a tray below the grid. Click or tap a piece to select it, then click on the grid to place it. Use R or the scroll wheel to rotate, F to flip. On mobile, use the rotate and flip buttons. Pieces snap to the grid and can be picked up for repositioning. A ghost preview shows where the piece will land. Complete the puzzle by filling every cell!
Last updated April 2026