5.5 parallelogram properties.notebook
December 06, 2010
Section 5.5 Properties of Parallelograms
Remember tomorrow is 2,4,6
1. Check Homework (10pts)
Notes, 5.1, 5.2, 5.3, 5.4
2. Go over ch4 exams
3. Section 5.5 This week, 5.6, 5.7, then Monday review for..
Next week, 50/50 group exam 50%
Inde exam 50%
Dec 4­10:12 AM
Coming up in 5.5 Examples for the EOC exam:
• Are opposite sides of a parallelogram always congruent? Why or why not?
• Are opposite angles of a parallelogram always congruent? Why or why not?
• Prove that the diagonals of a parallelogram bisect each other.
• Explain why if the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram.
• Prove that the diagonals of a rectangle are congruent. Is this true for any parallelogram? Justify your reasoning.
Dec 1­11:17 AM
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5.5 parallelogram properties.notebook
December 06, 2010
Recall: (definitions)
Parallelogram: is a quadrilateral with two pairs of parallel sides. Rhombus: is an equilateral parallelogram.
Rectangle: is a parallelogram with four congruent angles. Square: is an equilateral rectangle. is an equangular rhombus.
is a regular quadrilateral. Dec 4­10:04 AM
Theorem: A quadrilateral is a parallelogram if and only if its opposite sides are congruent. x
q
p
y
Dec 2­4:25 PM
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5.5 parallelogram properties.notebook
December 06, 2010
Theorem: A quadrilateral is a parallelogram if and only if its opposite angles are congruent. a
b
Dec 2­4:21 PM
Theorem: A quadrilateral is a parallelogram if and only if its adjacent angles are supplementary. a
b
Dec 2­4:23 PM
3
5.5 parallelogram properties.notebook
December 06, 2010
Theorem: A quadrilateral is a parallelogram if and only if its diagonals bisect each other. Dec 2­4:28 PM
Section 5.5 p. 281 #1­6, 15­19
Dec 2­4:30 PM
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