Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. 8.2 Perimeter

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 22 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. The perimeter of a polygon is the distance around the polygon, which is the sum of the lengths of its sides. Perimeter

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 33 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. llw w P  2l  2w Perimeter of a Rectangle Perimeter  2 length  2 width width length width length

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 44 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. s sss P  4s Perimeter of a Square Perimeter  4 ∙ side side

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 55 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. b a c P  a  b  cP  a  b  c Perimeter of a Triangle a b c P  side a  side b  side c

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 66 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. The circumference is the distance around a circle. diameter Circumference ÷ diameter always results in the same ratio, π. This number is named “pi” and is approximately (≈) equal to or Circumference of a Circle

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 77 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Circumference of a Circle r d Circumference = 2 π radius Circumference = π diameter or C = 2π r or C = π d