I often find myself going down unexpected rabbit holes, and today was no exception. While on a quest to create a more engaging quadrilateral hierarchy for a 3rd-grade team, I found myself pondering the age-old question: Is a parallelogram a trapezoid? As it turns out, the answer is both yes and no!
I know. You’re wondering how it can be a trapezoid and yet not a trapezoid simultaneously. The answer lies in the definition of a trapezoid. The Oxford Dictionary defines a trapezoid as “a quadrilateral with only one pair of parallel sides.” So, according to this definition, the answer is no, which makes our math ‘program’ give incorrect information (that is a whole other post). However, many define it as a quadrilateral with at least one pair of parallel sides, which makes a parallelogram a trapezoid and our math ‘program’ correct.
In my math mind, a parallelogram is separate from a trapezoid. According to the hierarchy, the broad spectrum is quadrilateral. Below that there are either two or three main categories of quadrilaterals: kite, trapezoid, and sometimes parallelogram. Then, the parallelogram can be further broken down into rectangle and rhombus. Those can both be broken down into a square.
For the purposes of our district, I followed the current ‘curriculum’ where a parallelogram is a trapezoid. Below are the two variations of the poster.
So, what are your thoughts? Is a parallelogram a trapezoid or not?
Nowa Techie 