Question 80411
Set up an equation for the diagonal, d , of the square
{{{d = sqrt(2)*s}}} where s is a side
{{{4 = sqrt(2)*s}}}
solve for s
{{{s = 4 / sqrt(2)}}}
multiply top and bottom by {{{sqrt(2)}}}
{{{s = 2*sqrt(2)}}} answer
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{{{C = 5.68*10^9}}}
you know that
{{{C = 2*pi*r}}} where r is the radius
{{{2*pi*r = 5.68*10^9}}}
solve for r
{{{r = 5.68*10^9 / (2*pi)}}}
{{{r = 9.04000077*10^10}}} answer