Question 481169
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi,
Standard Form of an Equation of a Circle is {{{(x-h)^2 + (y-k)^2 = r^2}}}
where Pt(h,k) is the center and r is the radius

Midpoint Pt(x,y):  ( {{{(x[1] + x[2])/2}}}, {{{(y[1] + y[2])/2  )}}})
A( 4, -3 ) 
B( -2, 7 )  Center of the circle is Pt(1,2)
{{{(x-1)^2 + (y-2)^2 = r^2}}}
D = {{{sqrt ((x[1]-x[2])^2+(y[1]-y[2])^2))}}}
A( 4, -3 ) 
B( -2, 7 ) d = {{{sqrt(6^2 + (-10)^2)= sqrt(136)}}} d = 11.6619, r =  5.83
{{{(x-1)^2 + (y-2)^2 = 34}}}

{{{drawing(300,300, -10,10,-10,10,  grid(1),
circle(1, 2,0.4),
circle(1, 2,5.83),
circle(4, -3,0.4),
circle(-2, 7,0.4),
graph( 300, 300,-10,10,-10,10  ))}}}