Analysis: The spatial diagonal of the cuboid is the diameter of the circumscribed sphere, so first find the spatial diagonal of the cuboid = ﹙ a? +b？ +c？ ﹚。 Know the diameter and divide it by 2 to get the radius. Then the volume is obtained according to the volume formula of the ball.
Basic introduction:
The center of the inscribed spherical surface of a polygon is the intersection of all bisectors of dihedral angles of the polygon.
The position of the center o of the polygon circumscribed sphere can be determined by the following methods:
1, and point o is the intersection of two straight lines passing through the nonparallel plane of the polyhedron and circumscribed the center of the circle and perpendicular to the nonparallel plane.
2. Point O is the intersection of three planes passing through the midpoints of nonparallel edges of polyhedron and perpendicular to these edges.
3. Point O is the intersection of a straight line passing through the center of the circumscribed circle of a face and perpendicular to the plane ∑ of the circle and a plane passing through the midpoint of an edge that is not parallel to ∑ and perpendicular to the edge.