9-1 Area of Rectangles and Parallelograms Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day Lesson Quizzes Lesson Quizzes

9-1 Area of Rectangles and Parallelograms Warm Up 1. What is the perimeter of a square with side lengths of 15 in.? 2. What is the perimeter of a rectangle with length 16 cm and width 11 cm? 60 in. 54 cm

9-1 Area of Rectangles and Parallelograms Problem of the Day Two wibbles equal four wabbles, and eight wabbles equal two bibbles. If a square has a perimeter of 16 wibbles, what is its area in square bibbles? 4 square bibbles

9-1 Area of Rectangles and Parallelograms MA.6.A.3.4 Solve problems given a formula. Also MA.6.A.4.2 Sunshine State Standards

9-1 Area of Rectangles and Parallelograms Vocabulary area

9-1 Area of Rectangles and Parallelograms The area of a figure is the amount of surface it covers. We measure area in square units.

9-1 Area of Rectangles and Parallelograms Additional Example 1: Estimating the Area of an Irregular Figure Estimate the area of the figure. Count full squares: 19 red squares. Count almost-full squares: 9 blue squares. Count squares that are about half- full: 4 green squares = 2 full squares. Do not count almost empty yellow squares. Add = 30 The area of the figure is about 30 mi. 2

9-1 Area of Rectangles and Parallelograms Check It Out: Example 1 Estimate the area of the figure. about 18 mi 2. = 1mi 2

9-1 Area of Rectangles and Parallelograms

9-1 Area of Rectangles and Parallelograms Additional Example 2: Finding the Area of a Rectangle Find the area of the figure. Write the formula. Substitute 15 for l and 9 for w. Multiply. A = lw A = 15 9 A = 135 The area is about 135 in in. 9 in.

9-1 Area of Rectangles and Parallelograms Check It Out: Example 2A Find the area of each rectangle.. 70 ft. 11 ft. A = lw = 70 × 11 = 770 The area is 770 ft. 2

9-1 Area of Rectangles and Parallelograms Check It Out: Example 2B Find the area of each rectangle.. 9 mi. 12 mi. A = lw = 12 × 9 = 108 The area is 108 mi. 2

9-1 Area of Rectangles and Parallelograms You can use the formula for the area of a rectangle to write a formula for the area of a parallelogram. Imagine cutting off the triangle drawn in the parallelogram and sliding it to the right to form a rectangle. The area of a parallelogram = bh. The area of a rectangle = lw. The base of the parallelogram is the length of the rectangle. The height of the parallelogram is the width of the rectangle.

9-1 Area of Rectangles and Parallelograms Additional Example 3: Finding the Area of a Parallelogram Find the area of the parallelogram. Write the formula. Multiply. A = bh 2 ft 1 2 A = __ 1 4 Substitute 2 for b and 1 for h. 1 2 __ 1 4 A = 5 2 __ 5 4 A = or ___ 1 8 __ The area is 3 ft __ ft

9-1 Area of Rectangles and Parallelograms Check It Out: Example 3A Find the area of each parallelogram. 8 ft 7 ft A = bh = 8 × 7 = 56 The area is 56 ft. 2

9-1 Area of Rectangles and Parallelograms Check It Out: Example 3B Find the area of each parallelogram. 12 m 5.6 m A = bh = 5.6 × 12 = 67.2 The area is 67.2 m. 2

9-1 Area of Rectangles and Parallelograms Additional Example 4: Recreation Application Jessika is going to tile a kitchen that measures 13 ft by 17 ft. Some floor space is taken up by an island that measures 3 ft by 6 ft. How much area remains to be tiled in the kitchen? Substitute for l and w in A = lw. Use the order of operations. The area of the kitchen to be tiled is 203 ft 2. floor area To find the area to be tiled, subtract the area of the island from the area of the floor. kitchen area to be tiledisland –= (13 17) ‏ (3 6) ‏ n –= 221 – 18 = 203

9-1 Area of Rectangles and Parallelograms Check It Out: 4 What is the area that will be painted? 18 × 8 = 144; 3 × 2.5 = 7.5; (3 × 7.5) = The area that will be painted is ft ft 3 ft 2.5 ft 8 ft = The figure shows a wall of an office with three identical windows. An employee is going to paint this wall of the office

9-1 Area of Rectangles and Parallelograms Standard Lesson Quiz Lesson Quizzes Lesson Quiz for Student Response Systems

9-1 Area of Rectangles and Parallelograms Lesson Quiz Find the area of each figure What is the area of a parallelogram with base 16 in. and height 10 in.? 4. A square fish pond that is 6 ft long is surrounded by a square walk that is 18 ft long. What is the area covered by the walk? 41.4 m 2 48 ft in ft 2

9-1 Area of Rectangles and Parallelograms 1. Find the area of the figure. A m 2 B m 2 C m 2 D m 2 Lesson Quiz for Student Response Systems

9-1 Area of Rectangles and Parallelograms 2. Find the area of the figure. A. 60 ft 2 B. 70 ft 2 C. 80 ft 2 D. 90 ft 2 Lesson Quiz for Student Response Systems

9-1 Area of Rectangles and Parallelograms 3. Find the area of a parallelogram with base 19 ft and height 11 ft. A. 209 ft 2 B. 214 ft 2 C. 216 ft 2 D. 220 ft 2 Lesson Quiz for Student Response Systems