Say what a trapezoid is in your very own words. Compare your meaning with a partner.

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## IM Commentary

The function of this job is for students come articulate a an interpretation for a trapezoid. There are two competing definitions for "trapezoid":

The exclusive definition of a trapezoid states that a trapezoid has exactly one pair of opposite political parties parallel.

The inclusive an interpretation states the a trapezoid has at least one pair the opposite political parties parallel.

Sometimes people say trapezoids "have one pair the opposite political parties parallel," which pipeline it ambiguous whether there have the right to be much more than one or not. The second part of the task pushes student to it is in clear about which version they intend. Due to the fact that of the treatment students must take through definitions, this task draws heavily on MP6, resolve precision.

After students have articulated meanings for us or v a partner, the class should talk about the an interpretation together. The class should decision on a single an interpretation that they every agree on, as the suggest of having plainly articulated interpretations is that us all know we room talking about the exact same thing. When both meanings are legitimate, the advantage to the inclusive an interpretation is that any theorem confirmed true because that a trapezoid is likewise true because that a parallelogram. Furthermore, in their examine The classification of quadrilaterals (Information period Publishing, 2008), Usiskin et al. Conclude,

The preponderance of advantages to the inclusive meaning of trapezoid has actually caused every the posts we might find ~ above the subject, and most college-bound geometry books, to favor the inclusive definition.

The inclusive meaning sets increase a relationship between parallelograms and trapezoids the is exactly analogous to to the relationship in between squares and rectangles; the meaning for rectangles consists of squares in the same method that the inclusive an interpretation of trapezoids contains parallelograms.