A quadrilateral with only one pair of parallel sides. The parallel sides of the trapezoid. The angles formed by the bases and legs of a trapezoid. The non-parallel sides of a trapezoid.

A trapezoid with congruent legs. Segment connecting the midpoints of the legs. A quadrilateral that has two pairs of consecutive congruent sides, but opposite sides are not congruent.

4 - 3 _____ 4 - 1 1 __ 3 2 - 0 _____ 6 - 0 2 __ 6 1 3 ∥ 2 - 4 _____ 6 - 4 -2 __ 2 -1 3 - 0 _____ 1 - 0 3 __ 1 not parallel parallel sides

Isosceles Trapezoid Theorem congruent D B Converse of Isosceles Trapezoid Theorem base angles Diagonals of Isosceles Trapezoid Theorem congruent AC DB

isosceles trapezoid K K 50° supplementary 180° 50° 130° L L 130° 50° 130° 130°

E (7, 5) mDE = 5 - 3 _____ 7 - 1 1 __ 3 = mCF = 2 - 0 6 - 0 mCD = 1 - 0 3 - 0 = 3 mEF = 5 - 2 7 - 6 Quadrilateral CDEF is a parallelogram because the opposite sides are parallel. m∠C = m∠B = 135° m∠A = 180° - m∠B m∠A = 180° - 135° m∠A = 45° m∠D = m∠A = 45°

1 __ 2 AB CD AB CD A = 1 __ 2 (b1 + b2) b1 & b2 are the bases of the trapezoid

1/2 PQ SR 1/2 16 9 16 9 12.5

MN = 1/2(b1 + b2) MN = 1/2(12 + 30) MN = 1/2(42) MN = 21ft

perpendicular AC BD ≅ ≅

congruent R R m∠S m∠Q 360° 88° 70° 360° 2 158° 360° 2m∠T = 202° 101°

m∠G + m∠I + m∠H + m∠J = 360° m∠G + m∠G + 85° + 75° = 360° 2m∠G + 160° = 360° 2m∠G = 200° m∠G = 100°