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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 Click to view Lesson Videos 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