CROSSWORD PUZZLE

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Across
  1. 3. a plane figure with four equal sides and four right angles
  2. 6. a way of arranging identical plane shapes so that they completely cover an area without overlapping.
  3. 7. a figure whose sum of all the angles gives 180 degrees.
Down
  1. 1. a synonym of corner in mathematics
  2. 2. In geometry, a figure of five sides and five angles.
  3. 4. the pentagon tiles are all ....
  4. 5. who founded the 15th type of pentagonal tiling.