Question 336371
If the diameter is {{{d=28}}}, then the radius is {{{r=d/2=28/2=14}}} yards. So {{{r=14}}}



Area:


{{{A=pi*r^2}}} Start with the area of a circle formula.



{{{A=pi*(14)^2}}} Plug in {{{r=14}}}.



{{{A=(3.14159)*(14)^2}}} Replace {{{pi}}} with {{{3.14159}}} (note: Use more digits of {{{pi}}} to get better accuracy).



{{{A=(3.14159)*(196)}}} Square {{{14}}} to get {{{196}}}.



{{{A=615.75164}}} Multilpy  {{{3.14159}}} and {{{196}}} to get {{{615.75164}}} (this figure is approximate).



{{{A=615.752}}} Round to the nearest thousandth.



So the area of the circle is roughly 615.752 square yards.


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Circumference:



{{{C=2pi*r}}} Start with the circumference of a circle formula.



{{{C=2pi*(14)}}} Plug in {{{r=14}}}.



{{{C=2(3.14159)*(14)}}} Replace {{{pi}}} with {{{3.14159}}} (note: Use more digits of {{{pi}}} to get better accuracy).



{{{C=6.28318*(14)}}} Multiply 2 and {{{3.14159}}} to get {{{6.28318}}}.



{{{C=87.96452}}} Multiply {{{6.28318}}} and {{{14}}} to get {{{87.96452}}}.



So the circumference of a circle with a radius of {{{14}}} yards is about {{{87.96452}}} yards.



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Jim