A piece of wall can be visually disintegrated from the whole into a separate triangle by plunging a diagonal of light from edge to edge on the wall; that is, side to floor, for instance.
I have had many troubles in my life, but the worst of them never came.
The 'transition' involves the transfer of power from one president to another. In recent times, the incoming President has designated a Director of the Transition, a team leader, to oversee and administer the orderly transfer of power.