1. Area of Parallelograms
8-4
Area of Parallelograms
Course 2
Warm Up
Problem of the Day
Lesson Presentation

2. Area of Parallelograms
Course 2
8-4
Area of Parallelograms
Warm Up
Find each product.
1. 8  12
2. 3
 6.3
 7 96 1 2
 5 1 3 2 3 18
59.22
24.5

3. Area of Parallelograms
Course 2
8-4
Area of Parallelograms
Problem of the Day
How many 3 ft by 2 ft rectangles can you cut from one 8 ft by 4 ft rectangle? How much will be left over?
5 pieces; 2 ft2 left over

4. Area of Parallelograms
Course 2
8-4
Area of Parallelograms
Learn to find the area of rectangles and other parallelograms.

5. Insert Lesson Title Here
Course 2
8-4
Area of Parallelograms
Insert Lesson Title Here
Vocabulary
area

6. Area of Parallelograms
Course 2
8-4
Area of Parallelograms
The area of a figure is the number of unit squares needed to cover the figure. Area is measured in square units.
AREA OF A RECTANGLE
The area A of a rectangle is the product of its length l and its width w. w
A = lw l

7. Additional Example 1: Finding the Area of a Rectangle
Course 2
8-4
Area of Parallelograms
Additional Example 1: Finding the Area of a Rectangle
Find the area of the rectangle.
4.5 in.
7.4 in.
A = lw
Use the formula.
A = 7.4 · 4.5
Substitute for l and w.
A = 33.3
Multiply.
The area of the rectangle is 33.3 in2.

8. Area of Parallelograms
Course 2
8-4
Area of Parallelograms
Try This: Example 1
Find the area of the rectangle.
6.3 in.
8.2 in.
A = lw
Use the formula.
A = 8.2 · 6.3
Substitute for l and w.
A = 51.66
Multiply.
The area of the rectangle is in2.

9. Area of Parallelograms
Course 2
8-4
Area of Parallelograms
For any parallelogram that is not a rectangle, you can cut a right triangle-shaped piece from one side and move it to the other side to form a rectangle.
Base
Height
The base of a parallelogram is the length of one side. The height of a parallelogram is the perpendicular distance from the base to the opposite side.

10. AREA OF A PARALLELOGRAM
Course 2
8-4
Area of Parallelograms
The base of the parallelogram is the length of the rectangle. The height of the parallelogram is the width of the rectangle.
Helpful Hint
AREA OF A PARALLELOGRAM
The area A of a parallelogram
is the product of its base b
and its height h. h b
A = bh

11. Additional Example 2: Finding the Area of a Parallelogram
Course 2
8-4
Area of Parallelograms
Additional Example 2: Finding the Area of a Parallelogram
Find the area of the parallelogram.
A = bh
8 m
A = 16
· 8
A = 128
16 m
The area of the parallelogram is
128 m2.

12. Area of Parallelograms
Course 2
8-4
Area of Parallelograms
Try This: Example 2
Find the area of the parallelogram.
A = bh
6 cm
A = 12
· 6
A = 72
12 cm
The area of the parallelogram is
72 cm2.

13. Additional Example 3: Measurement Application
Course 2
8-4
Area of Parallelograms
Additional Example 3: Measurement Application
A carpenter is using 2-ft by 2-ft square tiles to cover a rectangular floor. If the area of the floor is 150 ft2, what is the least number of tiles the carpenter will need?
First find the area of each tile.
A = lw
Use the formula for the area of a square.
A = 2 · 2
Substitute 2 for l and 2 for w.
A = 4
Multiply.
The area of each square tile is 4 ft2.

14. Additional Example 3 Continued
Course 2
8-4
Area of Parallelograms
Additional Example 3 Continued
To find the number of tiles needed, divide the area of the floor by the area of one tile.
150 ft2
4 ft2
= 37.5
Since covering the floor requires more than 37 tiles, the carpenter would need at least 38 tiles.

15. Insert Lesson Title Here
Course 2
8-4
Area of parallelograms
Insert Lesson Title Here
Try This: Example 3
Amanda decided to use 1.5-ft by 1.5-ft square tiles to cover a rectangular floor. If the area of the floor is 200 ft2, what is the least number of tiles Amanda will need?
First find the area of each tile.
A = lw
Use the formula for the area of a square.
A = 1.5 · 1.5
Substitute 1.5 for l and 1.5 for w.
A = 2.25
Multiply.
The area of each square tile is 2.25 ft2.

16. Area of Parallelograms Insert Lesson Title Here
Course 2
8-4
Area of Parallelograms
Insert Lesson Title Here
Try This: Example 3 Continued
To find the number of tiles needed, divide the area of the floor by the area of one tile.
200 ft2
2.25 ft2
≈ 88.9
Since covering the floor requires more than 88 tiles, Amanda would need at least 89 tiles.

17. Area of Parallelograms Insert Lesson Title Here
Course 2
8-4
Area of Parallelograms
Insert Lesson Title Here
Lesson Quiz: Part 1 13 1 8
in2
105 or
Find the area of each figure. 3. 1 2
3.5 ft 2 ft
7 ft
24.5 ft2 1 4 5 ft 4. 28 1 2
ft2 57 or
7 ft 1 2 4
12 ft
84 ft2 1 2 6 ft

18. Insert Lesson Title Here
Course 2
8-4
Area of Parallelogram
Insert Lesson Title Here
Lesson Quiz: Part 2
5. Suzanne is planning to use 1 ft by 0.5 ft tiles to finish her bathroom floor. If her floor is 7 ft by 10 ft, how many tiles will she need?
140 tiles