Find the perimeter of a quadrilateral with vertices at c (-1,2), d (-2,-1), e (2,-2), and f (1,1). round to the nearest hundredth when necessary.

a.) 10.92
b.) 12.68
c.) 13.43
d.) 18.27

To answer, find the distance from point C to D, point D to E, point E to F, and point F to C. The formula for the distance is,
                                     d = sqrt ((x2 - x1)² + (y2 - y1)²)
  Point C to D                d1 = sqrt ((-3 - -2)² + (1 - 4)²) = 3.16 units
  Point D to E                d2 = sqrt ((1 - -3)² + (0 - 1)²) = 4.12 units
  Point E to F                 d3 = sqrt ((-1 - 1)² + (2 - 0)²) = 2.83 units
  Point F to C                 d4 = sqrt ((-1 - -2)² + (2 - 4)²) = 2.23 units 
Then, add up all the distances and the answer is 12.34 units. The closest answer is letter D.  Credit:Meerkat

12+3b -1=-5-b -12-1+5=-b-3b -8=-4b