A tangential quadrilateral is a convex quadrilateral with an incircle, i.e., a circle
inside the quadrilateral that is tangent to all four sides. In [4] and [5] we reviewed
and proved a total of 20 different necessary and sufficient conditions for a convex
quadrilateral to be tangential. Of these there were 14 dealing with different distances
(sides, line segments, radii, altitudes), four were about circles (excluding
their radii), and only two were about angles. In this paper we will prove five more
such characterizations concerning angles and circles. First we review two that can
be found elsewhere.