Geometry puzzle

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Across
  1. 4. triangle,A polygon with four sides and four right angles
  2. 7. quadrilateral with two pairs of adjacent sides that are equal in length
  3. 10. line that intersects two or more coplanar lines at different points
  4. 13. that tapers to a point
  5. 14. plane figure with three straight sides and three angles
  6. 15. triangle,A triangle with three equal sides
  7. 16. intersection point of three or more lines
Down
  1. 1. point where the three altitudes of a triangle meet
  2. 2. three-dimensional object with a circular base and a curved
  3. 3. triangle,A triangle with one right angle
  4. 5. ratio of the circumference of a circle to its diameter
  5. 6. polygon with seven sides
  6. 8. triangle,A triangle with two equal sides
  7. 9. line that divides a segment into two equal parts
  8. 11. amount of space inside a two-dimensional shape
  9. 12. polygon with five