1-5 Using Formulas in Geometry
                       Rigor
   Apply formulas for perimeter, area, and 
   circumference.
                    Relevance
   Formulas help determine the amount 
   needed and cost of materials.
 Holt McDougal Geometry
  1-5 Using Formulas in Geometry
     The perimeter (P) is the sum of the 
     side lengths of the figure. Units for 
     length (ft, m, in)
     The area (A) is the number of 
     square units of a given size that 
     exactly cover the figure. Square 
               2     2    2
     units (ft , m , in )
 Holt McDougal Geometry
  1-5 Using Formulas in Geometry
     Rectangle   Triangles            Circles
  h
           b
       A   = bh                      2
                   A  = ½ bhA  = r
       b=base,                     Circumference (C)
      h=height                     C = 2r    C = d
                                    r = radius
                                   d = diameter
 Holt McDougal Geometry
  1-5 Using Formulas in Geometry
    The base b can be any side of a 
    triangle.
     
    The height h is a segment from a 
    vertex that forms a right angle with a 
    line containing the base.
 Holt McDougal Geometry
  1-5 Using Formulas in Geometry
          Example 1: Finding Perimeter and Area
   Find the perimeter and area of each figure.
 Holt McDougal Geometry