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2. Today we are going to find the Area of Parallelograms

3. Area The number of square units that are needed to cover the surface of a figure. Polygon Any closed plane figure made of line segments.

4. copyright©amberpasillas2010 Circle the polygons below. Regular Polygon Polygon with all sides congruent and all angles congruent.

5. The area of a rectangle is equal to the base times the height. Also known as length times width. height base (h) (b) A = bh A = bh is the same as A = lw

6. copyright©amberpasillas2010 What is the area of the rectangle ? 2 in. 6 in. 2 6x 12in. 2 12 in 2 or square inches

7. copyright©amberpasillas2010 A square is a special rectangle. Since the base and the height are the same size, we call them sides ( s ) instead of base and height. s height = s s base = s A= s 2

8. copyright©amberpasillas2010 What is the area of the square ? 4 m. 4 4 x 16m. 2 16 m 2 or square meters

9. copyright©amberpasillas2010 Given the formula for area of a rectangle, we are going to use that information to derive the formula for the area of a parallelogram Watch carefully not to miss it!

10. Draw a straight line from the top corner perpendicular to the base Cut that triangle and move it to the other side What shape does it make? Rectangle

11. copyright©amberpasillas2010 What is the formula for area of a parallelogram ? Use this information to find the area of a parallelogram A has the same area as a rectangle! h base = b height = h h b

12. copyright©amberpasillas2010 4 cm. 90º 2 cm. = 8 cm. 2 Check to see if you got it right.

13. copyright©amberpasillas2010 4 cm. 90º 2 cm. = 8 cm. 2 Cut off the piece at the dotted line.

14. copyright©amberpasillas2010 4 cm. 90º 2 cm. = 8 cm. 2 Cut off the piece at the dotted line.

15. copyright©amberpasillas2010 4 cm. 90º 2 cm. = 8 cm. 2 Move this piece to the other side.

16. copyright©amberpasillas2010 4 cm. 90º 2 cm. = 8 cm. 2 Move this piece to the other side.

17. copyright©amberpasillas2010 4 cm. 90º 2 cm. = 8 cm. 2 Now you have a rectangle A = 8 square cm. or 8 cm. 2 Let’s check it with the area of a rectangle. How many squares do you see?

18. copyright©amberpasillas2010 What is the area of this parallelogram ? 7 cm. 5 cm. 5 7 x 35cm. 2 35 square centimeters or 35 cm. 2

19. copyright©amberpasillas2010 What is the area of this parallelogram ? 6 ft. 5 ft. 5 6 x 30ft. 2 30 square feet or 30 ft. 2

20. copyright©amberpasillas2010 Area of a Parallelogram # 3 5 in 3 in A = b x h A = 5 x 3 = 15 in 2 To find the area for a parallelogram use what you know about area of a rectangle. A = base x height

21. copyright©amberpasillas2010