Definition #1: an isosceles trapezoid is a trapezoid with exactly one pair of parallel sides and whose none parallel sides are congruent.

Definition #2: an isosceles trapezoid is a trapezoid with one pair of parallel sides and with the other pair of sides congruent.

a) Explain how isosceles trapezoid are related to rectangles under each Definition?

b) How are these Definitions related to the Definition of trapezoid ?

c) a quadrilateral has vertices at (-a,0), (a,0), (b,c) and (d,c). Under Definition #1, what conditions must be b and d satisfy if the quadrilateral is an isosceles trapezoid ? Under Definition #2, what conditions must be b and d satisfy if the quadrilateral is an isosceles trapezoid ?

d) Are the two Definitions equivalent? why or why not?