Transcript SD 3.3 B-D Building Quadrilaterals.pptx

Math CC7/8 – Be Prepared
On Desk:
1. Pencil
2. Math Journal
3. Learning Log
1.
Parent Signature?
4. Quiz w/Signature?
Learning Log:
• HW:
Reminders:
• Parent Sig. on Quiz & LL
• Quiz Retake Mon/Tue in SDR
• SD Test Thursday 9/24
As a group, build the quadrilaterals on SD p. 66 #1-4
with Polystrips. Use labsheet 3.3 to help organize
your work.
Fundraiser – Turn in Monday!
Tasks for Today
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HW- questions/issues?
Finish yesterday’s Lesson?
Learning Check – SD 3.1/3.2
SD Lesson 3.3 B-D
Begin HW?
Use Polystrips and/or Virtual Polystrips in Groups
Many different
shapes can be
constructed with
these side lengths.
(isosceles trapezoid!)
Cannot build a quadrilateral
because 3+5+10 is less than
20!
Many different
shapes can be
constructed with
these side lengths.
(parallelograms, or
kites)
Many different
quadrilaterals, but
none will ever be a
parallelogram.
No!
The sum of the 3 shortest side lengths must
be greater than the longest side length.
Yes!
If it is possible to make one quadrilateral from
4 side lengths, it is possible to make many
different shapes from the same lengths.
Parallelograms (including rectangles)
require opposite sides to be equal.
Squares (rhombuses too) require all 4
sides to be equal.
The triangle holds firm or rigid until the
sides themselves buckle!
If you push down on a vertex, it deforms
into a different shape.
The diagonal brace makes it rigid because
it makes 2 triangles!
For both triangles and quadrilaterals –
• Each side must be less than the sum of the
others.
Triangles are rigid figures.
Quadrilaterals and other polygons are NOT!
This is why triangles are used in building
structures.