Monkeymore Sudoku

Avoidable Rectangle

المستوى 6 · Orange Belt (Green Stripe)

المتطلب السابق: Unique Rectangles

Overview

Avoidable Rectangle is similar to Unique Rectangle but involves solved cells. When three cells of a rectangle are already solved with two alternating values, the fourth cell must avoid completing the deadly pattern.

How It Works

  1. Find four cells forming a rectangle across two boxes.
  2. Three corners are already solved, using two values that alternate.
  3. The fourth (unsolved) cell has one of these values as a candidate.
  4. Eliminate that candidate to prevent the deadly pattern that would allow multiple solutions.

Example

Cells r4c9, r4c7, r7c9, and r7c7 form a rectangle across 2 boxes. Three corners are determined with values 5 and 7.

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Tips & Patterns

  • Avoidable Rectangles use the same uniqueness logic as Unique Rectangles but with solved cells.
  • Types 2, 3, and 4 parallel the UR types.
  • Look for rectangles where three corners are filled with two alternating digits.