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

OBJECTIVES 8.2 Perimeter Slide 3Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. aFind the perimeter of a polygon. bSolve applied problems involving perimeter.

8.2 Perimeter PERIMETER OF A POLYGON Slide 4Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. A polygon is a closed geometric figure with three or more sides. The perimeter of a polygon is the distance around it, or the sum of the lengths of its sides.

EXAMPLE 8.2 Perimeter a Find the perimeter of a polygon. 2 Slide 5Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc.

8.2 Perimeter PERIMETER OF A RECTANGLE Slide 6Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The perimeter of a rectangle is twice the sum of the length and the width, or 2 times the length plus 2 times the width:

EXAMPLE 8.2 Perimeter a Find the perimeter of a polygon. 3 Slide 7Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. Find the perimeter of a rectangle that is 7.8 ft by 4.3 ft.

8.2 Perimeter PERIMETER OF A SQUARE Slide 8Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. The perimeter of a square is four times the length of a side:

EXAMPLE 8.2 Perimeter a Find the perimeter of a polygon. 5 Slide 9Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc.

EXAMPLE 8.2 Perimeter b Solve applied problems involving perimeter. 6 Slide 10Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. Jaci is adding crown molding to the top edge of each wall in her rectangular dining room, which measures 14 ft by 12 ft. How many feet of trim will be needed? If the crown molding sells for $2.25 per foot, what will the trim cost?

EXAMPLE 8.2 Perimeter b Solve applied problems involving perimeter. 6 Slide 11Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. 1. Familiarize. We make a drawing and let P = the perimeter.

EXAMPLE 8.2 Perimeter b Solve applied problems involving perimeter. 6 Slide 12Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. 3. Solve. 2. Translate.

EXAMPLE 8.2 Perimeter b Solve applied problems involving perimeter. 6 Slide 13Copyright 2012, 2008, 2004, 2000 Pearson Education, Inc. 4. Check. The check is left to the student. 5. State. The 52 ft of crown molding that is needed will cost $117.