My geometry book is really confusing in the thorems there missing parts which I can't figure out. Here are a few of them.

The measure of an obtuse secant-tangent angle with its vertex on a circle is ________.

If two secants (or chords) intersect in the interior of a circle, the measure of any angle is __________.

If two secants intersect in the exterior of a circle, the measure of the angle is ___________.