Surely, you do not want a paraelogram to be a special case of an isosceles trapezoid, of a trapezoid yes, but not isosceles. Otherwise, there would be nothing to an isosceles trapezoid except a rectangle. You surely want two fo teh sides to be parallel and the other pair antiparallel with repect to those two.
On Mon, 10 Nov 1997, Guy F. Brandenburg wrote:
> David Rome wrote: > > > > I am having a spirited discussion with a colleage as to whether or not > > the definition of a kite allows it to be considered to be a rhombus. > > The general definition of a kite is a quadrilateral with two sets of > > consecutive congruent disjoint sides. The question is: what is meant > > by disjoint? Different length, or just separatable at the vertices? > > My colleague maintains that a rhombus cannot be a kite, since all its > > sides are congruent, thus, non-disjoint. Some material I have seen, > > including venn diagrams of parallelograms, includes kites as rhombuses > > when both sets of sides are congruent. What do you think? > > I would have kites be rhombuses if both pairs of congruent adjacent > sides are congruent. But I would also have parallelograms be special > cases of isosceles trapezoids where there are 2 pairs of congruent > parallel sides. But most textbooks have trapezoids be quadrilaterals > with exactly one pair of parallel sides, so I'm in the minority on that > one, too. >