1. Holt CA Course 1 10-3 Area of Parallelograms Warm Up Find each product. 1. 8  12 2. 3 3. 9.4  6.3 4. 3.5  7 96 59.22 1212  5 1313 24.5 18 2323 56 3 or

2. Holt CA Course 1 10-3 Area of Parallelograms AF3.1 Use variables in expressions describing geometric quantities (e.g., P = 2w + 2l, A = bh, C =  d–the formulas 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 California Standards 1212

3. Holt CA Course 1 10-3 Area of Parallelograms Vocabulary area base height

4. 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. The base of a parallelogram is the length of one side. Its height is the perpendicular distance from the base to the opposite side. h b Area = 15 square units

5. Holt CA Course 1 10-3 Area of Parallelograms

6. Holt CA Course 1 10-3 Area of Parallelograms Find the area of the parallelogram. Finding the Area of a Parallelogram 8 m 16 m A = bh A = 16 · 8 A = 128 The area of the parallelogram is 128 m 2. Use the formula. Substitute for b and h. Multiply.

7. Holt CA Course 1 10-3 Area of Parallelograms Find the area of the parallelogram. 6 cm 12 cm A = bh A = 12 · 6 A = 72 The area of the parallelogram is 72 cm 2. Use the formula. Substitute for b and h. Multiply.

8. Holt CA Course 1 10-3 Area of Parallelograms Find the area of the rectangle. 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.

9. Holt CA Course 1 10-3 Area of Parallelograms Find the area of the rectangle. 6.3 in. 8.2 in. A = lw A = 8.2 · 6.3 A = 51.66 The area of the rectangle is 51.66 in 2. Use the formula. Substitute for l and w. Multiply.

10. Holt CA Course 1 10-3 Area of Parallelograms The area of a playing field is 1,470 ft 2 and the length is 42 ft. What is the width of the field? A = lw 1,470 = 42 · w = The width of the playing field is 35 ft. Use the formula for the area of a rectangle. Substitute 1,470 for A and 42 for l. Divide both sides by 42 to isolate w. 1,470 42 42 · w 42 35 = w

11. Holt CA Course 1 10-3 Area of Parallelograms The area of a rectangular parking lot is 3,570 ft 2 and the width is 70 ft. What is the length of the parking lot? A = lw 3,570 = l · 70 = The length of the parking lot is 51 ft. Use the formula for the area of a rectangle. Substitute 3,570 for A and 70 for w. Divide both sides by 70 to isolate l. 3,570 70 l · 70 70 51 = l

12. Holt CA Course 1 10-3 Area of Parallelograms 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: Convert yards to feet. Step 2: Solve. 4 yd 5 yd A = l w A= 4 (3) x 5 (3) A= 12 x 15 The carpenter needs 180 ft 2 of flooring material.

13. Holt CA Course 1 10-3 Area of Parallelograms A carpenter is laying a tile floor measuring 5 yd by 7 yd. How many square feet of tile material does she need? 7 (3) x 5 (3) = A 21 x 15 = A 5 yd 7 yd The carpenter needs 315 ft 2 of tile material. L x W= A

14. Holt CA Course 1 10-3 Area of Parallelograms Lesson Quiz: Part I Find the area of each figure. 1. 2. 24.5 ft 2 4. 13 1818 in 2 105 8 or 28 1212 ft 2 57 2 =