Geometry CP, Jan 11
Quadrilaterals – Introduction and
Parallelograms
Book Section: 6-2
Essential Question: What four sided shapes are important and what do I
need to know about parallelograms?
Standards: CCSS G.CO.10, G.MG.3; G-3.5
Quadrilaterals
• Quadrilaterals – Four sided polygons
• Quadrilaterals to know:
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Parallelogram
Rectangle
Rhombus
Square
Kite
Trapezoid
Isosceles Trapezoids
Parallelogram
• Parallelogram – A quadrilateral with both pairs of
opposite sides parallel.
Rectangle
• Rectangle – A parallelogram with four right angles.
Rhombus
• Rhombus – A parallelogram with congruent sides.
Square
• Square – A rhombus with four right angles.
Kite
• Kite – A parallelogram with exactly two distinct pairs of
adjacent congruent sides.
Trapezoid
• Trapezoid – A parallelogram with exactly one pair of
opposite sides.
Isosceles Trapezoid
• Isosceles Trapezoid – A trapezoid each pair of base
angles congruent.
Properties of Parallelograms
• Parallelograms have a set of unique properties that are
defined by a full set of theorems (located on page 403 of
your text) that you should study and become familiar
with.
Properties of Parallelograms
Example 1A
Use Properties of Parallelograms
A. CONSTRUCTION In
suppose
mB = 32, CD = 80 inches, BC = 15 inches.
Find AD.
Example 1B
Use Properties of Parallelograms
B. CONSTRUCTION In
suppose
mB = 32, CD = 80 inches, BC = 15 inches.
Find mC.
Example 1C
Use Properties of Parallelograms
C. CONSTRUCTION In
suppose
mB = 32, CD = 80 inches, BC = 15 inches.
Find mD.
Example 2A
A. ABCD is a parallelogram. Find AB.
A. 10
B. 20
C. 30
D. 50
Example 2B
B. ABCD is a parallelogram. Find mC.
A. 36
B. 54
C. 144
D. 154
Example 2C
C. ABCD is a parallelogram. Find mD.
A. 36
B. 54
C. 144
D. 154
Diagonals
Example 3A
A. If ABCD is a parallelogram, find the value of x.
A. 2
B. 3
C. 5
D. 7
Example 3B
B. If ABCD is a parallelogram, find the value of p.
A. 4
B. 8
C. 10
D. 11
Example 3C
C. If ABCD is a parallelogram, find the value of k.
A. 4
B. 5
C. 6
D. 7
Examples
Classwork: Textbook p.408, 15-18
Homework: HW Due 1/15, 1-8