Math

• Exterior


  Outside
• Interior


  Inside
• Adjacent


  They must have common vertex and they must form a linear pair
• Linear pair


  They must have a common side
• Remote Interior Angles


  Not adjacent to the exterior angle
• Supplementary Angle


  The sum of their measure must be 180°
• Triangle Sum Theorem


  The sum of the Interior Angle of a triangle must be 180°
• Vertical Angles are always congruent
• The measure of an exterior angle of a triangle

  Is equal to the sum of the measures of the two remote Interior Angles
• Exterior Angle


  Is greater than the measure of any of the two remote Interior Angles in a triangle
• Remote Interior Angles


  Are less than the Exterior Angle in a triangle
• Exterior angle of a triangle

  An angle which forms a linear pair (adjacent) with one of the triangle's interior angles
• Triangle inequality theorem


  The sum of the lengths of any two sides of a triangle is greater than the length of the third side
• Applying triangle inequality theorem

  1. Identify pair of two sides

  2. Compare sum of two sides to third side

  3. If sum of two sides is greater than third side, then it can form a valid triangle
• The lengths of the sides of a triangle should satisfy the triangle inequality theorem
• Angle-side relationship theorem


  The largest angle is opposite the longest side, the smallest angle is opposite the shortest side
• The largest angle is always opposite the longest side, and the smallest angle is always opposite the shortest side
• The angle-side inequality theorem states that if one angle is larger than the other angle, the side opposite the larger angle is the longer side
• The side-angle inequality theorem states that if one side is longer than the other side, then the angle opposite the longer side is the larger angle
• The sum of the three angles in a triangle is 180 degrees