Task# What is a Trapezoid? (Part 1)

Illustrative MathematicsVaries

The purpose of this task is for students to articulate a definition 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 sides parallel. The inclusive definition states that a trapezoid has at least one pair of opposite sides parallel. Sometimes people say trapezoids 'have one pair of opposite sides parallel,' which leaves it ambiguous whether there can be more than one or not.