program inscribed_bicycle
  implicit none
  real(8) :: x(3), y(3), r(3), a, b, c, h
  real(8) :: a2, b2, c2
  character(64) :: s
  read(*,*) x(1), y(1)
  read(*,*) x(2), y(2)
  read(*,*) x(3), y(3)
  r(1) = sqrt((x(2)-x(1))**2.d0+(y(2)-y(1))**2.d0)
  r(2) = sqrt((x(3)-x(2))**2.d0+(y(3)-y(2))**2.d0)
  r(3) = sqrt((x(1)-x(3))**2.d0+(y(1)-y(3))**2.d0)
  a = minval(r)
  c = maxval(r)
  b = sum(r)-a-c
  a2 = a*a
  b2 = b*b
  c2 = c*c
  h = sqrt(2.d0*(a2*b2+b2*c2+c2*a2)-a2*a2-b2*b2-c2*c2)/(2.d0*c)
  write(s,'(f32.16)') c*h/(a+b+c+2.d0*h)
  write(*,'(a)') trim(adjustl(s))
  stop
end program inscribed_bicycle