Answer
See below
Work Step by Step
Call $A(-220,220); B(200,40)$ and $O(0,0)$
Find the midpoint of the line segment
$M_1=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})=(\frac{-220+0}{2},\frac{220+0}{2})=(-110,110)\\M_2=(\frac{200+0}{2},\frac{40+0}{2})=(100,20)$
Find m:
$m_1=\frac{y_2-y_1}{x_2-x_1}=-1\\m_2=\frac{1}{5}$
Calculate the slope of the perpendicular bisector:
$m_1=1\\m_2=-5$
Use point-slope form:
$y_1=x+220\\x_2=-5x+520$
Find the intersection:
$y_1=y_2\\x+220=-5x+520\\6x=300\\x=50$
Find y: $y=50+220=270$
Find the distance from O: $d=\sqrt (0-50)^2+(0-270)^2\approx274.6$
The diameter is $2\times274.6\approx549.2$
