[tex](x - 4) {}^{2} + (y - 1) {}^{2} = r {}^{2} [/tex]
passes through ( 4 , -4 )
[tex](4 - 4) {}^{2} + ( - 4 - 1) {}^{2} = r {}^{2} [/tex]
[tex]r {}^{2} = ( - 5) {}^{2} [/tex]
[tex]r {}^{2} = 25[/tex]
[tex]r = \sqrt{25} = 5[/tex]
Your radius is 5 units
[tex]c = 2\pi \: r \\ c = 2 \times 3.14 \times 5 \\ c = 31.4[/tex]
Place your center at the point x=4 and y=1
Then take your radius 5 units by going straight down left right or up by 5 units
AND DRAW