Paper Corners: Shakashaka

Paper Corners is a Shakashaka logic puzzle: place black triangles in a grid until every white region forms a rectangle. Some rectangles sit straight; others tilt at 45 degrees. The numbered squares tell you how many neighboring squares need triangles. Solve 90 original pages in nine chapters. Start with small boards, then work through larger pages up to 8 × 8. Choose a page by difficulty or follow the chapters in order. A short introduction teaches the rules. Four optional technique lessons let you practice triangle clues, white squares, and rectangle edges. If you get stuck, a hint marks a cell and explains the deduction. Undo and redo let you revisit any move. Play a daily page or choose an earlier date from the daily archive. An unfinished daily page stays available after midnight. Keep your finished pages in a composition library, with the white rectangles traced in indigo. Mark favorites, share an image, export printable sheets, or send a playable page link to a friend. Play offline on iPhone and iPad, without timers, lives, scores, ads, or purchases. The paper-and-ink design supports light and dark appearance, larger text, VoiceOver, Reduce Motion, and Increase Contrast. Paper Corners is independent of Nikoli.