Question 740162
given;

diameter of the fountain: {{{d=5ft}}}

flagstone walkway is {{{18in}}} wide

convert 
 {{{18in}}} to ft: {{{18in=(18/12)ft=1.5ft}}}

to find out how much fence you need, you need a perimeter of circle made from fountain base and flagstone walkway together

{{{drawing( 500, 500, -10, 10, -10, 10,
  grid( 1 ),
  green( circle( 0, 0, 5 ) ),locate(0.5,1.5,r=2.5ft),locate(4,4.5,r1=1.5ft),
blue( circle( 0, 0, 8 ) ),blue(line( 4.9,6.3, 3, 4 )),
  red(line( 0, 0, 3, 4 ))
)}}}

since a radius of that circle is equal to radius of fountain base plus {{{18in}}}, first find radius of fountain base:

given diameter of the fountain {{{d=5ft}}}; so, radius is {{{r=5ft/2=2.5ft}}}

then, radius of fountain base and flagstone walkway together is {{{r[1]=2.5ft+1.5ft=4ft}}}

now find perimeter of that circle:

{{{P=2r[1]pi}}}

{{{P=2*4ft*3.14}}}

{{{P=25.12ft}}}


so,

1. you need {{{25.12ft}}} fencing

2. if fencing cost ${{{4.00}}} per yard, then we need to convert ft to yd

 {{{25.12ft=8.3733yd}}}

then cost is ${{{8.3733 *4.00}}} => ${{{33.49}}}