What is the circumcentre of the triangle with vertices (0, 0), (8, 0) and (0, 6)?

The triangle is right-angled at the origin, so its circumcentre is the midpoint of the hypotenuse joining (8, 0) and (0, 6): (4, 3). ((8/3, 2) is the centroid and (2, 2) the incentre.)