Math

• Polygon


  Close-plane figure formed by 3 or more line segments.
• Convex polygon


  Interior angle is less than 180°
• Non-convex polygon


  Have at least one internal angle greater than 180°
• Angle bisector


  Ray that divides an angle into two congruent angles
• Vertical angles


  Also called opposite angles. Create 2 pairs of opposite rays.
• Vertical angle theorem


  Any vertical angle will always have equal degree measurements
• Corresponding angles


  Angles that have the same relative position
• If two adjacent angles are supplementary, then they are called ____

  Linear pairs
• Transversal Line


  Formed when a line intersects two parallel lines
• Alternate interior angle theorem

  If 2 parallel lines are cut by a transversal, the alternate interior angles formed are congruent.
• Corresponding angle theorem


  If two parallel lines are cut by a transversal line, then the pairs of corresponding angles are congruent.
• Interior angles of a polygon


  Angles located inside a polygon are called interior angles.
• Triangle sum theorem


  Sum of the measurements of all the interior angles of any triangle is 180°.
• What is the formula for the no. of diagonals formed of a polygon 


  n(n-3)/2
• What is the general formula for the sum of interior angles of a polygon

  180 (n-2)
• Formula for the measurement of an interior angle of a regular polygon


  180(n-2)/n
• acute triangle


  All interior angles are acute
• Right triangle


  Has one interior angle that is exactly 90°.
• Obtuse Triangle 


  Has precisely one obtuse interiot angle
• Scalene Triangle


  All of its sides are non-congruent.
• Isosceles


  Has two congruent sides
• Equilateral Triangle


  All sides are congruent
• Congruent Triangles


  Two triangles are congruent if all their corresponding sides and angles are congruent.
• Corresponding Parts of a Triangle are Congruent (CPCTC)

  If two triangles are congruent, their corresponding parts (sides and angles) are also congruent.
• Exterior angle is the sum of___

  Opposite interior angles
• Sum of exterior angle of triangle is___

  360°
• Side-angle-side (SAS) postulate


  If two corresponding sides and their included angle (the angle between them) of a triangle are congruent, the triangles are congruent.
• Angle-side-angle (ASA) postulate


  If two corresponding angles and their included side (the side located between them) of a triangle are congruent, the triangles are congruent.
• Side-side-side (SSS) postulate 


  If all three sides of two triangles are congruent, they are congruent.
• Isosceles angle theorem


  If two sides of a triangle are congruent, then the angles opposite those sides are congruent.
• Triangle inequality Theorem


  The sum of any two sides of a triangle is always greater than or equal to the third side.
• Two triangles are similar if they have___

  . All their angles are equal

  . Corresponding sides are in the same ratio