Quadrilaterals

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Quadrilaterals

• Dr. Beth McCulloch Vinson
• Athens State University
• PT3 Grant Funding, Summer 2000

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Quadrilaterals

• Quad means four. Why would all of these
  shapes be called quadrilaterals?
• Each shape has four sides.

trapezoid
square
rhombus
parallelogram
rectangle
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In this slide show you will learn that we
identify quadrilaterals by
their angles

• and the length of their sides.

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Square

• A square has four sides that are each the same
  length.
• It also has four right angles (perfect corners).

1
4
3
2
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Rhombus

• A rhombus has four sides that are each the same
  length.
• But it has two acute and two obtuse angles.

acute
obtuse
acute
obtuse
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Square and Rhombus

• A square and a rhombus both have four sides that
  are the same length. So, how are they different?

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Square and Rhombus

• A rhombus can be thought of as a slanted square.
• If we push on the left-hand side of this square,
  it might end up looking like

a rhombus.
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The only difference between a square and a
rhombus is their angles.
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Trapezoid

• A trapezoid has four sides.
• Two sides are parallel.
• The opposing two sides are not parallel.

Those are not parallel.
Those are parallel.
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Rectangle

• A rectangle has four sides two long sides and
  two short sides.
• Two sides are parallel.
• The opposing two sides are also parallel.
• It also has four right angles.

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Parallelogram

• A parallelogram has four sides two long sides
  and two short sides.
• Two sides are parallel.
• The opposing two sides are also parallel.
• But, it has two acute and two obtuse angles.

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Rectangle and Parallelogram

• A parallelogram can be thought of as a slanted
  rectangle.
• If we push on the left-hand side of this
  rectangle, it might end up looking like

a parallelogram.
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The only difference between a rectangle and a
parallelogram is their angles.
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Use the following table to make comparisons using
the quadrilaterals.For example, what do a
square and a rectangle have in common?
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Quadrilaterals

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The End

• A Project Developed for
• Preparing Tomorrows Teachers to Use Technology
  (PT3)
• By Dr. Beth McCulloch Vinson
• Athens State University, School of Education
• http//www.athens.edu/vinsobm