8'5 Rhombi and Squares

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8.5 Rhombi and Squares
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Rhombus -a quadrilateral with 4 congruent sides
(pl rhombi)
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Properties of Rhombi

• all properties of parallelograms
• Thm 8.15 - diagonals of a rhombus are
  perpendicular
• Thm 8.16 - if diagonals are perpendicular
  ?rhombus (converse of Thm. 8.15)
• Thm 8.17 - diagonals of rhombus bisect opposite
  angles

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Examples
x
y2 - 31
56
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Square - quadrilateral that is both a rhombus and
a rectangle(so it has ALL same props as those)
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Example

• Given vertices A(1,3), B(-3,1), C(-1,-3),
  D(3,-1), determine if the polygon is a
  parallelogram, a rectangle, rhombus, or square.
  List ALL that apply.

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How do they all tie together?

• Make a Venn diagram relating quadrilaterals,
  parallelograms, rhombi, rectangles, and squares.

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Assignment

• 8.5 worksheet