Trapezoid
 Is a quadrilateral with exactly one pair of parallel sides. The parallel sides are the bases
 A trapezoid has two pairs of base angles. For example in the trapezoid ABCD,
ÐA and ÐB are one pair of base angles, and ÐC and ÐD are the second pair.
 The non parallel sides are the legs of the trapezoid.
Isosceles Trapezoid: If the legs of the trapezoid are congruent then the trapezoid is an Isosceles trapezoid.
THEOREMS:
 If a trapezoid is isosceles, then each pair of base angles is congruent.
If trapezoid ABCD is isosceles, then ÐA @ ÐD and ÐB @ ÐC.
 If a trapezoid has a pair of congruent base angles, then it is an isosceles trapezoid ABCD is isosceles.
If ÐA @ ÐD and ÐB @ ÐC. then ABCD is isosceles.
 A trapezoid is isosceles if and only if its diagonals are congruent.
Trapezoid ABCD is isosceles if and only if AC @ BD.
 Midsegment Theorem for Trapezoids:
The midsegment of a trapezoid is parallel to each base and its length is one half the sum of the lengths of the bases. If MN is the midsegment of trapezoid ABCD, then MN // AB, MN // DC, and MN = 1/2(AB+CD)
Directions:
1) For the trapezoid ABCD shown below find the measures of angle A, angle C and angle D.
2) Answer the following questions and write at least 5 examples of your own.
