How to Play Rectangles (Shikaku)
Rectangles, known in Japan as Shikaku ("divide by squares"), is a tiling puzzle.
The rules
- Divide the grid into rectangles (squares count) that cover every cell and don't overlap.
- Each rectangle contains exactly one number.
- That number is the rectangle's area, the count of cells in it.
First steps
- A prime number (2, 3, 5, 7, 11) can only be a strip, 1 wide.
- A number in a corner, or boxed in by other numbers, often has one shape left.
- Any cell that only one number could reach belongs to that number's rectangle.
On kawu
- Drag from one corner of a rectangle to the opposite corner to draw it. A new rectangle replaces any it overlaps. Tap a rectangle to remove it. With a keyboard, Space marks the two corners.
- Rectangles with the wrong area, no number or two numbers show their number in red.
- Every puzzle has one solution that logic can reach. The daily puzzle is 9×9.
Frequently asked questions
Can a rectangle be a square in Shikaku?
Yes. A 4 can be a 2×2 square as well as a 1×4 or 4×1 strip.
Can rectangles overlap or leave gaps?
No. The rectangles tile the whole grid: every cell is in exactly one rectangle.
Last updated 2026-10-20