Today, as they focus on their great building, I tell them I want them to be thinking about quadrilaterals. I ask them to think, then say, "What is the one characteristic that all quadrilaterals have in common?" (4 sides) "What prefix means four?" (quad) "What part of the word means side?" (lateral).
I have this interactive quadrilateral up on the projector screen and let a student come over and manipulate it for about 30 seconds. I ask students to touch their nose if they see a polygon that is not a quadrilateral. I watch for this and later call on that student and work with them if needed to see if they need further clarification. All of the shapes in the interactive are quadrilaterals.
I tell them that prior to getting back to work on their great buildings, we will discuss some of the attributes of quadrilaterals.
As we go over the following, the emphasis is on discussion; can the students explain, compare, critique and categorize what they are seeing.
We discuss and review the properties of the sides and angles of various quadrilaterals. This is more complex topic than it may appear to be because there are so many instances of categories within categories and sometimes the definition used by mathematicians (example - trapezoid) is not the same one as is commonly used by elementary teachers.
I start the review of quadrilaterals with this short clip that reviews squares, rectangles, and parallelograms.
After that, we also discuss trapezoids. Note the definition comments below.
trapezoids (I use the definition most accepted by mathematicians - a quadrilateral with at least one set of parallel sides, though the trapezoid we are most accustomed to seeing has ONLY 1 set of parallel sides. I point that out to the students, that this will be the most common interpretation but it is not accepted by mathematicians).
Time permitting, I have them look at their Shapes Reference and come up with a possible definition for a kite. We have already discussed this in small group conferences in the previous days.
For enrichment, it is also an option to have them discuss the differences they see in the types of triangles. Have them focus on the angles (acute - less than 90 degrees or obtuse, greater than 90 degrees, or, of course, a right angle) and whether or not the sides are congruent.
Some students will finish up their buildings today and can prepare to talk about them using the sheet that was passed out at the beginning, Creating My Own Great Building -Thinking it Through. Other students will need additional time.
Students rotate to 2 different student's work stations to observe their classmates work. 1/2 the class stays with their work in progress, the other 1/2 of the class rotates.