Parallelograms

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Lesson 6-1

• Parallelograms

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Parallelogram
Definition
A quadrilateral whose opposite sides are parallel.
Symbol
a smaller version of a parallelogram
Naming

• A parallelogram is named using all four vertices.
• You can start from any one vertex, but you must
  continue in a clockwise or counterclockwise
  direction.
• For example, the figure above can be either
  ABCD or ADCB.

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Properties of Parallelogram
A
B
P
C
D
1. Both pairs of opposite sides are congruent.
2. Both pairs of opposite angles are congruent.
3. Consecutive angles are supplementary.
4. Diagonals bisect each other but are not
congruent
P is the midpoint of .
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Examples
H
K
M
P
L

1. Draw HKLP.
2. HK _______ and HP ________ .
3. mltK mlt______ .
4. mltL mlt______ 180?.
5. If mltP 65?, then mltH ____,mltK ______ and
   mltL ____.
6. Draw the diagonals with their point of
   intersection labeled M.
7. If HM 5, then ML ____ .
8. If KM 7, then KP ____ .
9. If HL 15, then ML ____ .
10. If mltHPK 36?, then mltPKL _____ .

PL
KL
P
P or K
115
115
65?
5 units
14 units
7.5 units
36?
(Alternate interior angles are congruent.)