Properties of Trapezoid

• Trapezoid


  A quadrilateral in which one and only one pair of opposite sides are parallel
• Trapezoid


  • One pair of opposite sides are parallel
  • The other pair of opposite sides are not parallel
• Parallel sides of a trapezoid

  Called the bases
• Non-parallel sides of a trapezoid


  Called the legs
• Angles formed by a base and a leg


  Called the base angles
• Isosceles trapezoid


  A trapezoid where the legs are congruent
• Isosceles trapezoid


  • Legs are congruent
  • Base angles are congruent
  • Diagonals are congruent
• Median of a trapezoid

  A segment that joins the midpoints of the non-parallel sides (legs)<|>It is parallel to the bases and has a length equal to one half the sum of the lengths of the bases
• Finding the length of the median of a trapezoid

  1. Measure the lengths of the bases

  2. Add the lengths of the bases

  3. Divide the sum by 2
• If CF = 7.5, then EF = 15 and BC = 20, AD = 30
• If BC = 12, AD = 24, and EF = 18, then EB = 24
• Finding the value of x in an isosceles trapezoid

  1. Substitute the given values into the equation

  2. Solve for x
• In an isosceles trapezoid, the diagonals intersect at right angles
• In an isosceles trapezoid, the base angles are congruent
• In an isosceles trapezoid, the diagonals are congruent
• In an isosceles trapezoid, the median is perpendicular to the bases and bisects them
• In an isosceles trapezoid, the sum of the base angles is 180 degrees
• In an isosceles trapezoid, the sum of the angles at the vertex is 180 degrees
• If BD = 7x and CA = 2x + 5, then x = 1