Quick Start Expectations1. Come in and sit quietly.2. Fill in planner and HWRS:

3. Work on Warm-up:If true, provide an example. If false, provide a

counterexample (prove that it is not true). 1. True or False: You can make a triangle using any three lengths for sides. 2. True or False: You can make a quadrilateral

using any four lengths for sides.

Textbook: CMP3 Grade 7 Unit: Shapes and Designs pp. 76-86, #10-16, 29-31

NotebookProblem 3.3: Building Quadrilaterals 9/30/14

What combinations of side lengths can be used to make a quadrilateral? How many different shapes are possible?

(Underline 2 or 3 key words in your question.)

p. 66

Group TaskParts A and B – Use Labsheet 3.3Parts C and D – Complete in NotebookLearning Facilitator: Make sure everyone is together on the same problem and that everyone answers questions completely before going on.Resource Manager: Get materials(polystrips & labsheets) & ensure they are put back neatly.Participation Captain: Encourage everyone to try constructing quadrilaterals and participate in the discussion.Reporter/Recorder: Raise hand to ask teacher a question if everyone in the group has the same question.Note: Everyone should be prepared to share answers in the class discussion.

p. 66-67

6 10 12 12 Yes

These sides cannot be used to build a quadrilateral, because 3+5+10 is less than 20.

3 5 10 20 No

8 8 10 10 Yes

READ the INSTRUCTIONS CAREFULLY!

Yes, the sum of any three side lengths of the quadrilateral must be greater than the fourth side.

Yes, if you can make one quadrilateral from four side lengths, it is often possible to make

many different shapes from the same side lengths.

To build parallelograms, including rectangles, the opposite side lengths must be equal.

To build squares, including rhombuses, all four side lengths must be equal.

The triangle will hold firm or rigid until the sides themselves buckle.

The quadrilateral will deform quickly into different shapes (unless the connections at the vertices are very tight).

The stress test explains why triangles are used to hold structural shapes firm.

Using a diagonal makes a quadrilateral frame into a rigid figure, because it makes two triangles.

When building triangles and quadrilaterals, each side must be less than the sum of the others.

Triangles are rigid figures.

Quadrilaterals & other polygons with more than three sides are not.

When building a structure, which shape would you use more frequently?

Exit Ticket:

• What quadrilaterals would be useful in building things? Why?

Homework:

Textbook: CMP3 Grade 7 Unit: Shapes and Designs pp. 76-86, #10-16, 29-31