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

Area of Parallelograms Course 2 8-4 Area of Parallelograms Warm Up Find each product. 1. 8  12 2. 3 3. 9.4  6.3 4. 3.5  7 96 1 2  5 1 3 2 3 18 59.22 24.5

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

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

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

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

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.

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 51.66 in2.

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.

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

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.

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.

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.

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.

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.

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.

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. 1. 2. 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

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