Welcome Parallelogram Experts!
Take out the following:
(1) Whiteboard and Whiteboard Pen
(2) “Discovering Properties of Parallelograms” from Friday
Tonight’s Homework
Pg. 395 #1-14, 22,24, 33-43 odd
Remember: Quiz on Tuesday: 6.1, 6.2, 1.6 and 3.5 of
your textbook
There is no parent signature sheet for the short week.
Tomorrow’s Quiz
Topics:
6.1 – Classifying Polygons / Sum of Interior and Exterior
Angles
1.6 – Midpoint and Distance Formula
3.5 – Slope formula
6.2 – Properties of Parallelograms
3 Things
Lets’ Warm-Up!
On Friday’s Exploration worksheet, write a summary of
what you learned after completing this packet.
Pretend a first grader wants to know about all the
properties of a parallelogram. How would you respond?
Be ready to share out!
Lets’ Warm-Up!
In class on Friday, we discussed #1-3.
For #4(c), discuss your answer with someone sitting
horizontal to you. Then write your solution on a
whiteboard.
Lets’ Warm-Up!
For #5(e), discuss your answer with someone sitting
vertical to you. Then write your solution on a whiteboard.
Lets’ Warm-Up!
For #6(d), discuss your answer with someone horizontal to
you. Then write your solution on a whiteboard.
Let’s Warm Up
On your whiteboard, draw a parallelogram that
includes all necessary tick marks and arch
marks.
6-2 Properties of Parallelograms
Learning Objective:
o SWBAT prove and apply properties of parallelograms to
solve problems
6-2 Properties of Parallelograms
Parallelogram
o A quadrilateral with two pairs of parallel sides.
o To write the name of a parallelogram, you use the symbol
.
Example/Non-Ex of Parallelograms
Example
Non-Example
6-2 Properties of Parallelograms
What question number does this correlate to on your
Exploration Worksheet?
6-2 Properties of Parallelograms
On your notes, write down the question number from your Exploration Packet that best
matches each theorem.
Example 1: Properties of Parallelograms
In CDEF, DE = 74 mm, DG = 31 mm, and mFCD = 42°.
Justify each solution.
(a) Find CF.
(a) Find mEFC.
(b) Find CF.
Whiteboards
In KLMN, LM = 28 in., LN = 26 in., and mLKN
= 74°. Justify each response.
a) Find KN.
b) Find mNML.
c) Find LO.
Example 2: Using Properties of
Parallelograms to Find Measures
WXYZ is a parallelogram.
(a) Find YZ.
(b) Find mZ.
Whiteboards
EFGH is a parallelogram.
(a ) Find JG
(b) Find FH.
Whiteboards
1. Opposite sides of a parallelogram are
____________ and congruent.
2. What do the slopes have to be if two lines
are parallel to each other?
Example 3: Parallelograms in the
Coordinate Plane
Three vertices of JKLM are J(3, –8), K(–2, 2), and L(2, 6).
Find the coordinates of vertex M.
Remember: When you are drawing a figure in the
coordinate plane, the name gives the order of the
vertices.
Example 3: Parallelograms in the
Coordinate Plane
• Step 1: Graph the points.
• Step 2: Find the slope of
KL by counting the units
from K to L.
• Step 3: Start at J and
count the same number
of units.
• Step 4: Use the slope
formula to verify that
Graphing Whiteboard
Three vertices of
PQRS are P(–3, –2), Q(–1,
4), and S(5, 0). Find the coordinates of vertex R.
Math Joke of the Day
• What do you call an urgent message sent
across a parallel network?
• A parallelogram!
Example 4: Properties of Parallelograms
in a Proof
Given: ABCD is a parallelogram.
Prove: ∆AEB  ∆CED
Proof:
Statements
1. ABCD is a parallelogram
Reasons
1. Given
2.
3.
 opp. sides 
 diags. bisect
each other
4. SSS Steps 2, 3
Whiteboards
QRST is a parallelogram. Find each measure. Justify your
reasoning.
(a) TQ
(b) mT
Whiteboards
In
PNWL, NW = 12, PM = 9, and mWLP = 144°. Find
each measure
(a) PW
(b) mPNW
Exit Ticket
Take out a half sheet of binder paper.
Title it: 6.2 Exit Ticket
Write your name in the upper right hand corner.
1. List the key ideas from todays lesson.
2. Draw and label every side and angle with the given
information for
PQRS :
a.
b.
c.
PQ= 10
QR=5
mS = 110°