The purpose of this activity is for students to use language to describe and distinguish quadrilaterals (MP6). This activity is stage 7 of the Which One? center. One partner chooses a shape from the gameboard without telling their partner. Their partner asks "yes" or "no" questions to figure out which shape their partner chose. Students focus on quadrilaterals. Students may rely on what they remember about categories of quadrilaterals, such as rectangles and rhombuses. They can also use informal language such as tilted, arrow, or red pattern block. The goal of the Activity Synthesis is to share and gather language which was helpful for distinguishing the quadrilaterals. 

This activity uses MLR2 Collect and Display. Advances: Conversing, Reading, Writing. 

• “¿Qué otras palabras o frases importantes deberíamos incluir en nuestra presentación?” // “Are there any other words or phrases that are important to include on our display?”
• As students share responses, update the display, by adding (or replacing) language, diagrams, or annotations.
• Remind students to borrow language from the display as needed.
• Invite previously selected students to share.
• Display the rhombus card that is not a square.
• “¿Qué nombres podemos usar para describir esta figura?” // “What are some names we can use to describe this shape?” (quadrilateral, diamond, parallelogram, rhombus)

The purpose of this activity is for students to sort quadrilaterals that they have worked with in previous grades. Students sort twice using categories of their own choosing and then again using parallel lines. Some categories students may choose include squares, rectangles, and rhombuses but they may also sort according to whether or not the shapes are labeled, how they are oriented, angle size, or side lengths (MP7).

As students work, encourage them to refine their descriptions of quadrilaterals using more precise language and mathematical terms (MP6).

If a student only sorts the cards in a way that makes sense to them, consider asking:

• Choose a shape that does have parallel lines and a shape that does not have parallel lines. “¿En qué se parecen y en qué son diferentes las rectas de estas dos figuras?” // “What is the same and different about the lines in these two shapes?”
• “¿Cómo puedes usar reglas para extender las rectas de las figuras?” // “How could you use rulers to extend the lines of the shapes?”

• Invite previously selected students to share.
• As students share their sorts, ask, “¿Qué características tienen en común todas estas figuras?” // “What attributes do all of these shapes have in common?”
• “¿De qué manera usaron rectas paralelas para clasificar los cuadriláteros?” // “How did you use parallel lines to sort the quadrilaterals?” (Some of the quadrilaterals did not have any parallel sides. Some had one pair of parallel sides. And some had two pairs of parallel sides.)
• Invite students to share examples of the quadrilaterals with no parallel sides, one pair of parallel sides, and two pairs of parallel sides.