1. Area of Parallelogram Lesson

2. Warm Up 1) What is the area of this shape?
OBJECTIVE: SWBAT use an efficient method to find the area of any parallelogram, and explain why it makes sense.
1) What is the area of this shape?
2) What is the area of this rectangle?
A = 24 sq units
A = 6 sq units
3) Which of the following shapes are parallelograms? Explain how you know.
A B. C D.
Shape A, B and D are all parallelograms!

3. Launch A Vocabulary What is the definition of a parallelogram?
A parallelogram is a quadrilateral that has 2 pairs of parallel sides. Opposite sides have the same length and opposite angles have equal measurements.

4. 12 1 2 3 4 5 6 7 8 9 10 11 Launch B (Wait time: 30 seconds)
Can you quickly find the area of this parallelogram by counting the unit squares? 12 1 2 3 4 5 6 7 8 9 10 11
Area = 12 square units

5. Launch B
Can you quickly find the area of this parallelogram by counting the unit squares?

6. “I don’t have all day. Counting takes way too long!”
Launch B
“I don’t have all day. Counting takes way too long!”
Your challenge:
Develop a more efficient method to determine the area of the parallelogram.

7. Launch C What does it mean to find an efficient method?
Remember the warm up problems?
A = 24 sq units
A = 6 sq units
Did you have to count squares to find the area of the rectangle?
NO!
Multiplying length x width is a more efficient method for finding the area of a rectangle than counting squares.

8. Launch C Let’s consider the first shape in the Warm Up.
How could decomposing (cutting) and composing (putting back together) into another shape help you find the area of this shape?

9. In 10 minutes you will be asked to stop and think about it!
Explore
Part 1 - (10 Min)
Work with your PARTNER to find an efficient method of finding the area of a parallelogram.
You will get a parallelogram and a pair of scissors. You can:
Write on the shape
Draw on it
Use scissors on it
Click on the timer!
1-Partners
2-Share Out
3-Worksheet
In 10 minutes you will be asked to stop and think about it!
HINT

10. Explore
You can decompose (cut) and recompose (paste) the parallelogram.
Think about how you can recompose it to make it easier and more efficient!
RETURN

11. Explore – Student Share Out
Part 2 - (3 Min)
Students share out work.

12. Fill out the top half of your worksheet.
Explore – Complete top half of worksheet Part 3 - (5 Min) – May work together. Then check on next few slides
Fill out the top half of your worksheet.

13. Summary – Sharing Questions #1-5
#1) Explain what you did to find a quicker way to find the area of the parallelogram.

14. Summary – Sharing Questions #1-5
#2) Draw the shapes you decomposed (cut apart) your parallelogram into. Do you know the names of these shapes?
#3) Did you create any new shape or shapes by composing (putting back together in a different way)?

15. Summary – Sharing Questions #1-5
original parallelogram
rectangle
8 cm
8 cm
12 cm
12 cm
#4) What dimensions does your new shape (rectangle) have?
The base is 12 cm.
The height is 8 cm.
#5) Can you identify those dimensions on the original parallelogram?
The base is
...?
also 12 cm.
The height is
...?
also 8 cm.

16. Assessment – Exit Ticket!
Complete and hand in the Exit Ticket before you leave!