  We revisit the Kerr black hole as cast in the Boyer-Lindquist, Kerr-Schild
and Weyl canonical coordinates, and calculate its total mass/energy and total
angular momentum by using linearized gravity along with its background Killing
isometries. We argue that the integration of the relevant gravitational flux
does not depend on the geometry of the closed and simply connected spatial
boundary provided it is also piecewise smooth.
