6.1 Classifying Quadrilaterals page 288

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6.1 Classifying Quadrilateralspage 288

• Obj 1 To define classify special types of
  quadrilaterals

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And why

• To use the properties of special quadrilaterals
  with a kite, as in Example 3.

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Seven important types of quadrilaterals

1. Parallelogram-has both pairs of opposite sides
   parallel
2. Rhombus-has four congruent sides
3. Rectangle-has four right angles
4. Square-has four congruent sides and four right
   angles
5. Kite-has two pairs of adjacent sides congruent
   and no opposite opposite sides congruent.

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Continued.

1. Trapezoid-has exactly one pair of parallel sides.
   (you have same side interior angles)
2. Isosceles trapezoid-is a trapezoid whose
   non-parallel opposite sides are congruent

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Classifying Quadrilaterals
Judging by appearance, classify ABCD in as many
ways as possible.
ABCD is a quadrilateral because it has four
sides.
6-1
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You try one

• Turn to page 289 and complete check understanding
  1 (top of page)

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Classifying by Coordinate Method

• Do you remember the slope formula?
• Do you remember the distance formula that finds
  the distance between two points?

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• Do you remember how to tell if two lines are
  parallel?
• Do you remember how to tell if two lines are
  perpendicular?

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Classifying Quadrilaterals
Determine the most precise name for the
quadrilateral with vertices Q(4, 4), B(2, 9),
H(8, 9), and A(10, 4).
6-1
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Classifying Quadrilaterals
(continued)
One pair of opposite sides are parallel, so QBHA
is a trapezoid.
Because QB HA, QBHA is an isosceles trapezoid.
6-1
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You try one

• Turn to page 289 and complete check understanding
  2 (bottom of page).

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Classifying Quadrilaterals
6-1
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Classifying Quadrilaterals
6-1
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You try one

• Turn to page 290 and complete check understanding
  3 (middle of page)

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Summary 6.1

• What are the seven types of quadrilaterals we
  have described today?
• How do you tell if two lines are parallel?
• How do you tell if two lines are perpendicular?

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6.2 Properties of Parallelograms (page 294)

• Obj 1 to use relationships among sides among
  angles of parallelograms
• Obj 2 to use relationships involving diagonals
  of parallelograms transversals

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• You can use what you know about parallel lines
  transversals to prove some theorems about
  parallelograms
• Theorem 6.1 p. 294---Opposite sides of a
  parallelogram are congruent

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Theorems Continued

• Theorem 6.2 page 295 Opposite angles of a
  parallelogram are congruent
• Theorem 6.3 page 296the diagonals of a
  parallelogram bisect each other
• Theorem 6.4 page 297If three of more parallel
  lines cut off congruent segments on one
  transversal, then they cut off congruent segments
  on every transveral.

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Properties of Parallelograms
GEOMETRY LESSON 6-2
6-2
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Properties of Parallelograms
GEOMETRY LESSON 6-2
Find the value of x in ABCD. Then find m
A.
6-2
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So x 5 and y 3.
6-2
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Summary 6.2

• What are the properties of parallelograms?
• Theorem 6.1-
• Theorem 6.2-
• Theorem 6.3-
• Theorem 6.4-

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Homework

• 6.1 page 290
• 2-26 E, 37-42