Improve

• Kinds of Polygons


  • Triangle - 3 sides
  • Quadrilateral - 4 sides
  • Pentagon - 5 sides
  • Hexagon - 6 sides
  • Heptagon - 7 sides
  • Octagon - 8 sides
  • Nonagon - 9 sides
  • Decagon - 10 sides
  • Hendecagon - 11 sides
• Convex Polygon


  All interior angles are less than 180°
• Concave Polygon


  At least one interior angle is greater than 180°
• Number of Triangles in a Polygon

  Number of sides - 2
• Sum of Interior Angles of a Polygon


  (n-2) * 180°, where n is the number of sides
• Corresponding Angles Postulate

  If two parallel lines are cut by a transversal, then the corresponding angles are congruent
• Alternate Interior Angles Theorem

  If two parallel lines are cut by a transversal, then the alternate interior angles are congruent
• Alternate Exterior Angle Theorem

  If two parallel lines are cut by a transversal, then the alternate exterior angles are congruent
• Same-side Interior Angles Theorem

  If two parallel lines are cut by a transversal, then the same side interior angles are supplementary