Warm Up Problem of the Day Lesson Presentation Lesson Quizzes

Warm Up Find each area. Round to the nearest tenth, if necessary. 1. a rectangle with length 10 cm and width 4 cm 2. a parallelogram with base 18 ft and height 12 ft 3. a triangle with base 16 cm and height 8 cm 40 cm2 216 ft2 64 cm2 78.5 in2

Problem of the Day Four squares are placed in a row, adjacent to one another. The square on the far left is 12 inches on a side. The perimeter of each of the other squares is half of the one to its left. What is the perimeter of the combined figure? 69 in. 3 3

Sunshine State Standards MA.6.G.4.2 Find the…areas of composite two-dimensional figures…using various strategies. Also MA.6.A.3.4

Additional Example 1A Finding the Area of Composite Figures by Adding Find the shaded area. Round to the nearest tenth, if necessary. Divide the figure into a rectangle and a trapezoid. area of the rectangle: A = bh A = 12 • 6 A = 72 m2

Additional Example 1 Continued Find the shaded area. Round to the nearest tenth, if necessary. area of the trapezoid: 2 m 8 m A = h(b1 + b2) 1 2 __ 2 m 4 m 6 m 6 m A = 2(4 + 2) 1 2 __ A = (12) 1 2 __ A = 6 m2 Add the area of the rectangle and the area of the trapezoid. total area: A = 72 + 6 = 78 m2.

Check It Out: Example 1 Find the shaded area. Round to the nearest tenth, if necessary.

Check It Out: Example 1 Continued Find the shaded area. Round to the nearest tenth, if necessary. Area of rectangle: 9 × 8 = 72 yd Area of triangle: (2)(9) = 9 yd Area of composite figure: 72 + 9 = 81 yd 2 1 _

Subtract the area of the triangle from the area of the rectangle. Additional Example 2: Finding the Area of Composite Figures by Subtracting 5 ft Find the shaded area. 6 ft 9 ft Subtract the area of the triangle from the area of the rectangle. 12 ft Area of the rectangle: Area of the triangle: A = bh 1 2 __ A = bh A = 12 • 9 = 108 ft2 A = • (6)(7) 1 2 __ A = • 42 = 21 ft2 1 2 __ Shaded area: A = 108 – 21 = 87 ft2

area of rectangle: A = lw = 16 8 = 128 Check It Out: Example 2 9 in. Find the shaded area. 5 in. 8 in. 16 in. area of rectangle: A = lw = 16 8 = 128 area of triangle: A = bh = (5 7) = (35) = 17.5 area of shaded area: A = 128 - 17.5 = 110.5 in 1 1 1 _ 2 2 2 2