Herons Formula

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Across
  1. 3. The total distance around the triangle.
  2. 5. "Unlike other rules, Heron’s doesn't need the ____."
  3. 8. A shape with three sides and three angles.
  4. 9. A triangle where all three sides are different.
Down
  1. 1. This is exactly half of the perimeter (s).
  2. 2. The symbol ​ is called a square ____.
  3. 4. A mathematical rule or equation.
  4. 6. The mathematician who created the formula.
  5. 7. The amount of space inside a shape.
  6. 9. "These are represented by the letters a,b, and c."