What do trapezoids look like

The definition given above is the one that is accepted within the mathematics community and, increasingly, in the education community. Many sources related to K education have historically restricted the definition of trapezoid to require exactly one pair of parallel sides.

This narrower view excludes parallelograms as a subset of trapezoids, and leaves only the figures like , , and. Parallelograms with special features, like right angles or all congruent sides or both , are given their own distinctive names: rectangle, rhombus, and square. The only special feature of a trapezoid that is awarded its own distinctive name is the second pair of parallel sides, which makes the special trapezoid a parallelogram.

No other distinctive names are used for trapezoids with special features like right angles or three congruent sides. The top and bottom of each side are parallel, but the top edge is usually shorter than the bottom edge. Similarly, a truss bridge often features multiple trapezoids along the sides that connect the base of the bridge to the structure overhead.

The steel or aluminum supports form adjacent trapezoids, with the two parallel sides being the top and bottom of the bridge sides. In modern architecture, trapezoids are often used to create unusual shapes, both for the entirety of a structure and for individual elements.

Compare your definition with a partner. Is this parallelogram a trapezoid according to your definition? IM Commentary 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. Solution A trapezoid is a quadrilateral with one pair of opposite sides parallel.

It can have right angles a right trapezoid , and it can have congruent sides isosceles , but those are not required. Sometimes people define trapezoids to have at least one pair of opposite sides parallel, and sometimes say there is one and only one pair of opposite sides parallel. The parallelogram fits the "at least one" version of the definition because it has two pairs of opposite sides parallel, therefore it falls into the category of being both a trapezoid and a parallelogram.

The parallelogram does not fit the "one and only one" version of the definition. So how students answer this depends on their definition.