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

Warm Up Find each product    Course Area of Parallelograms 1212 

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 ft 2 left over Course Area of Parallelograms

Learn to find the area of rectangles and other parallelograms. Course Area of Parallelograms

Vocabulary area Insert Lesson Title Here Course Area of Parallelograms

Course 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. A = lw w l

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

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

Course 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. 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. Base Height Base

Course 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 The area A of a parallelogram is the product of its base b and its height h. AREA OF A PARALLELOGRAM A = bh h b

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

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

A carpenter is using 2-ft by 2-ft square tiles to cover a rectangular floor. If the area of the floor is 150 ft 2, what is the least number of tiles the carpenter will need? Additional Example 3: Measurement Application Course Area of Parallelograms First find the area of each tile. A = lwUse 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 ft 2.

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

Try This: Example 3 Insert Lesson Title Here Course Area of parallelograms 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 ft 2, what is the least number of tiles Amanda will need? First find the area of each tile. A = lwUse 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 ft 2.

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

Lesson Quiz: Part 1 Find the area of each figure ft 2 Insert Lesson Title Here 84 ft 2 Course Area of Parallelograms 3.5 ft 7 ft ft ft in or ft or

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 Insert Lesson Title Here Course Area of Parallelogram