Download Geometry Lesson 6.2.notebook

Geometry Lesson 6.2.notebook
February 12, 2015
BELL RINGER
Find the measures of both an interior angle and an exterior angle of a regular 13 ­ gon.
(Round your answers to the nearest tenth, if necessary)
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Geometry Lesson 6.2.notebook
February 12, 2015
Parallelograms
Parallelogram ­ a quadrilateral with both pairs of opposite sides parallel.
Properties of Parallelograms (Theorems)
A. If a quadrilateral is a parallelogram, then its opposite sides are congruent.
B. If a quadrilateral is a parallelogram, then its opposite angles are congruent.
C. If a quadrilateral is a parallelogram, then its consecutive angles are supplementary.
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Geometry Lesson 6.2.notebook
February 12, 2015
D. If a parallelogram has one right angle, the it has four right angles.
If Angle J is a right angle in quadrilateral JKLM, then angle K, angle L, and angle M are also right angles.
In parallelogram ABCD, suppose
AB=2.5 feet, and BC=1 foot. Find each measure. a. DC =
b.
c. 3
Geometry Lesson 6.2.notebook
February 12, 2015
Diagonals of parallelograms
Theorems ­ If a quadrilateral is a parallelogram, then its diagonals bisect each other.
If ABCD is a parallelogram, then
QRST is a parallelogram, find x, y, and z.
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Geometry Lesson 6.2.notebook
February 12, 2015
Parallelograms and coordinate geometry
Determine the coordinates of the intersection of the diagonals of parallelogram FGHJ with vertices F(­2,4), G(3,5), H(2,­3), and J(­3,­4).
Since the point of intersection is the midpoint of each of the diagonals, use the midpoint formula. Both midpoints should be identical. So (0,0.5) is the intersection of the diagonals.
Try: Find the point of intersection of the diagonals of parallelogram RSTU with vertices R(­8,­2), S(­6,7), T(6,7), and U(4,­2).
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Geometry Lesson 6.2.notebook
February 12, 2015
P. 403 9­22, 31­36
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