Question 955158
the circumference of a circle is {{{C=2r*pi}}}
 a circle with center A({{{2}}},{{{3}}}) and passes through B({{{4}}},{{{5}}}) will have a radius {{{r}}} equal to distance between points A and B

*[invoke distance_formula 2, 3, 4, 5]

so, if we use the {{{d=2sqrt(2)}}}, then  {{{C=2r*pi}}} will be

 {{{C=2*2sqrt(2)*pi}}}

 {{{C=4sqrt(2)*pi}}} or as decimal

{{{C=4*2.83*3.14}}} 

{{{C=35.5448}}}

{{{C=35.51}}}


{{{drawing( 600, 600, -10, 10, -10, 10, 
circle(2,3,.12),circle(4,5,.12),circle(2,3,2sqrt(2)),
locate(2,3,A(2,3)),locate(4,5,B(4,5)),
line(2,3,4,5), locate(2.5,4.5,r(2sqrt(2))),
 graph( 600, 600, -10, 10, -10, 10,0 )) }}}