Shapes in Mathematics Crossword

1234567891011121314151617181920
Across
  1. 3. triangle with a 90 degree angle
  2. 6. all sides are equal in length and all angles are equal
  3. 9. triangle with all angles the same and all side lengths the same
  4. 13. has three sides
  5. 15. has four sides equal in length but not with equal angles
  6. 17. triangle with all angles less than 90 degrees
  7. 19. triangle with all side lengths different in size
  8. 20. triangle with one angle greater than 90 degrees
Down
  1. 1. not a shape
  2. 2. two pairs of parallel lines
  3. 4. four sides and only two are parallel
  4. 5. prefix meaning three
  5. 7. half of a circle
  6. 8. round shape
  7. 10. triangle with two equal side lengths
  8. 11. we also fly this in the sky
  9. 12. has four sides all equal in length with equal angles
  10. 14. prefix meaning four
  11. 16. has eight sides
  12. 18. prefix meaning five