2. CHAPTER 8 Geometry Slide 2Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. 8.1Basic Geometric Figures 8.2Perimeter 8.3Area 8.4Circles 8.5Volume and Surface Area 8.6Relationships Between Angle Measures 8.7Congruent Triangles and Properties of Parallelograms 8.8Similar Triangles

3. OBJECTIVES 8.3 Area Slide 3Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. aFind the area of a rectangle and a square. bFind the area of a parallelogram, a triangle, and a trapezoid. cSolve applied problems involving areas of rectangles, squares, parallelograms, triangles, and trapezoids.

4. 8.3 Area AREA OF A RECTANGLE Slide 4Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The area of a rectangle is the product of the length l and the width w:

5. EXAMPLE 8.3 Area a Find the area of a rectangle and a square. 2 Slide 5Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. Find the area of a rectangle that is 7 yd by 4 yd.

6. 8.3 Area AREA OF A SQUARE Slide 6Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The area of a square is the square of the length of a side:

7. EXAMPLE 8.3 Area a Find the area of a rectangle and a square. 3 Slide 7Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. Find the area of a square with sides of length 9 mm.

8. 8.3 Area b Find the area of a parallelogram, a triangle, and a trapezoid. Slide 8Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. A parallelogram is a four-sided figure with two pairs of parallel sides.

9. 8.3 Area AREA OF A PARALLELOGRAM Slide 9Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The area of a parallelogram is the product of the length of the base b and the height h:

10. EXAMPLE 8.3 Area b Find the area of a parallelogram, a triangle, and a trapezoid. 5 Slide 10Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. Find the area of this parallelogram.

11. 8.3 Area AREA OF A TRIANGLE Slide 11Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The area of a triangle is half the length of the base times the height:

12. EXAMPLE 8.3 Area b Find the area of a parallelogram, a triangle, and a trapezoid. 8 Slide 12Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. Find the area of this triangle.

13. 8.3 Area b Find the area of a parallelogram, a triangle, and a trapezoid. Slide 13Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. A trapezoid is a polygon with four sides, two of which, the bases, are parallel to each other.

14. 8.3 Area AREA OF A TRAPEZOID Slide 14Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The area of a trapezoid is half the product of the height and the sum of the lengths of the parallel sides (bases):

15. EXAMPLE 8.3 Area b Find the area of a parallelogram, a triangle, and a trapezoid. 9 Slide 15Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. Find the area of this trapezoid.

16. EXAMPLE 8.3 Area c Solve applied problems involving areas of rectangles, squares, parallelograms, triangles, and trapezoids. 11Lucas Oil Stadium Slide 16Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The retractable roof of Lucas Oil Stadium, the home of the Indianapolis Colts football team, divides lengthwise. Each half measures 600 ft by 160 ft. The roof opens and closes in approximately 9–11 min. The opening measures 293 ft across. What is the total area of the rectangular roof? What is the area of the opening? Source: HKS Sports and Entertainment

17. EXAMPLE 8.3 Area c Solve applied problems involving areas of rectangles, squares, parallelograms, triangles, and trapezoids. 11 Slide 17Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc.

18. EXAMPLE 8.3 Area c Solve applied problems involving areas of rectangles, squares, parallelograms, triangles, and trapezoids. 11 Slide 18Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. Each half of the retractable roof is a rectangle that measures 600 ft by 160 ft. The area of a rectangle is length times width, so we have

19. EXAMPLE 8.3 Area c Solve applied problems involving areas of rectangles, squares, parallelograms, triangles, and trapezoids. 11 Slide 19Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The total area of the two halves of the retractable roof is

20. EXAMPLE 8.3 Area c Solve applied problems involving areas of rectangles, squares, parallelograms, triangles, and trapezoids. 11 Slide 20Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. When the retractable roof is open, the dimensions of the opening are 600 ft by 293 ft. The area of this rectangle is When the roof is open, the opening is 175,800 ft 2.