_2-16-11_ Lesson 10-3 Area of Parallelograms _Class 2 Notes_ by dandanhuanghuang

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									10-3 Area of Parallelograms


    Preview

              Warm Up
              California Standards
              Lesson Presentation




Holt CA Course 1
10-3 Area of Parallelograms




Holt CA Course 1
10-3 Area of Parallelograms




Holt CA Course 1
10-3 Area of Parallelograms




Holt CA Course 1
10-3 Area of Parallelograms




Holt CA Course 1
10-3 Area of Parallelograms


    Warm Up
    Find each product.

    1. 8  12          96
                       56
    2. 3 1  5 1          or 18 2
           2       3    3       3
    3. 9.4  6.3       59.22
    4. 3.5  7         24.5



Holt CA Course 1
10-3 Area of Parallelograms

                   California
                   Standards
        AF3.1 Use variables in expressions
        describing geometric quantities (e.g.,
        P = 2w + 2l, A = 1bh, C = pd–the formulas
                          2
        for the perimeter of a rectangle, the area of
        a triangle, and the circumference of a circle,
        respectively).
        Also covered: NS2.1,           AF1.1,
        AF2.1, AF3.2


Holt CA Course 1
10-3 Area of Parallelograms




         Objective: You will learn how to
         (YWLHT) find the area of rectangles
         and other parallelograms.




Holt CA Course 1
10-3 Area of Parallelograms

                   Vocabulary
        area
        base
        height




Holt CA Course 1
10-3 Area of Parallelograms

       The area of a figure is the number
       of non-overlapping unit squares
       needed to cover the figure. Area is
       measured in square units.           Area = 15 square units

        The base of a parallelogram is the length of
        one side. Its height is the perpendicular
        distance from the base to the opposite side.
        For a rectangle, the base is the
        same as the length, and the height              h
        is the same as the width.                   b




Holt CA Course 1
10-3 Area of Parallelograms




Holt CA Course 1
10-3 Area of Parallelograms
     Example 1: Finding the Area of a Parallelogram

    Find the area of the parallelogram.




                   8m

              16 m




            The area of the parallelogram is 128 m2.


Holt CA Course 1
10-3 Area of Parallelograms
                      Check It Out! Example 2

    Find the area of the parallelogram.


               6 cm

           12 cm


                                          SMART Response Que
                                          To set the properties right click and select
                                          SMART Response Question Object->Properties...




   The area of the parallelogram
   is 72 cm2.


Holt CA Course 1
10-3 Area of Parallelograms

                   SMART Response Quiz Results (Correct answer:72)
                                    Skipped
                                      4%




                                               72
                                              96%




Holt CA Course 1
10-3 Area of Parallelograms
        Example 3: Finding the Area of a Rectangle

    Find the area of the rectangle.


                     4.5 in.

         7.4 in.




               The area of the rectangle is 33.3 in2.

Holt CA Course 1
10-3 Area of Parallelograms
                   Check It Out! Example 4

    Find the area of the rectangle.


                   6.3 in.

        8.2 in.

                                       SMART Response Que
                                       To set the properties right click and select
                                       SMART Response Question Object->Properties...




   The area of the rectangle
   is 51.66 in2.


Holt CA Course 1
10-3 Area of Parallelograms

                   SMART Response Quiz Results (Correct answer:51.66)
                                    33.26
                            49.86    4%
                                            50.36
                             4%
                                             4%
                       57.66
                        4%

                    52.92
                     4%
                   50.84
                    5%
                           516.6
                            5%

                                                       51.66
                                                        70%




Holt CA Course 1
10-3 Area of Parallelograms
                   Example 5: Finding Length or
                      Width of a Rectangle
   The area of a playing field is 1,470 ft2 and the
   length is 42 ft. What is the width of the field?




   The width of the playing
   field is 35 ft.


Holt CA Course 1
10-3 Area of Parallelograms
                   Check It Out! Example 6
    The area of a rectangular parking lot is
    3,570 ft2 and the width is 70 ft. What is the
    length of the parking lot?

                                       SMART Response Que
                                       To set the properties right click and select
                                       SMART Response Question Object->Properties...




                                     The length of the
                                     parking lot is 51 ft.

Holt CA Course 1
10-3 Area of Parallelograms

                   SMART Response Quiz Results (Correct answer:51)


                                   Skipped
                      3500    61     9%
                       4%     4%

                   37.42
                    5%




                                                    51
                                                   78%




Holt CA Course 1
10-3 Area of Parallelograms
             Example 7: Measurement Application
    A carpenter is laying a wood floor measuring
    4 yd by 5 yd. How many square feet of
    flooring material does she need?

    Step 1: Draw and label a diagram.
                                                  4 yd
    Step 2: Convert the units.
                                          5 yd




Holt CA Course 1
10-3 Area of Parallelograms
                   Example 7 Continued
    A carpenter is laying a wood floor measuring
    4 yd by 5 yd. How many square feet of flooring
    material does she need?
    Step 3: Find the area of the floor in square feet.
    A = lw   Use the formula for the
             area of a rectangle.                  12 ft

                                              15 ft




                              The carpenter needs 180 ft2
                              of flooring material.

Holt CA Course 1
10-3 Area of Parallelograms
                   Check It Out! Example 8
    A carpenter is laying a tile floor measuring 5
    yd by 7 yd. How many square feet of tile
    material does she need?
                                                    5 yd
    Step 1: Draw and label a diagram.
                                             7 yd
    Step 2: Convert the units.




Holt CA Course 1
10-3 Area of Parallelograms
               Check It Out! Example 8 Continued
    A carpenter is laying a tile floor measuring 5
    yd by 7 yd. How many square feet of tile
    material does she need?

    Step 3: Find the area of the tile                           15 ft
    floor in square feet.
                                               21 ft
     A = lw

                                        SMART Response Que
                                        To set the properties right click and select
                                        SMART Response Question Object->Properties...




  The carpenter needs 315 ft2
  of flooring material.

Holt CA Course 1
10-3 Area of Parallelograms


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Holt CA Course 1
10-3 Area of Parallelograms
                   Lesson Quiz: Part I
     Find each perimeter.
     1.              2.
                                         9 cm
                       5
                      __
                     4 6 ft


     3. What is the perimeter of a polygon with
        side lengths of 15 cm, 18 cm, 21 cm, 32
        cm, and 26 cm?
          112 cm


Holt CA Course 1
10-3 Area of Parallelograms
                      Lesson Quiz
     Find the circumference of each circle. Use
     3.14 as an estimate for p.
     1.                   2.




          C ≈ 25.12            C ≈ 18.84
          in.                  in.

     3. Find the circumference of a circle with
        diameter of 20 feet. Use 3.14 as an
     estimate C ≈ 62.8 p.
                 t for ft


Holt CA Course 1
10-3 Area of Parallelograms
                   Lesson Quiz: Part I

  Find the area of each figure.      105      1
                                         or 13 in2
                                      8       8
  1.                          2.


                   24.5 ft2



  3.                          4.
                                                57 or
                                                 2
                   84 ft2                   28 1 ft2
                                               2


Holt CA Course 1
10-3 Area of Parallelograms

                    Lesson Quiz: Part II

     5. Diego is building a rectangular platform
        measuring 36 in. by 54 in. What is the area of
        the platform in square feet?
        13.5 ft2




Holt CA Course 1

								
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