CAB
Dihedral angle
That is called an angle.
Right angle E. The vertex of any angle can also be used to name the angle.
PQ
m, r & y
An angle is formed where two lines meet. Parallel lines do not meet. Therefore they do not form an angle. So there is no angle to have a name. So no name.
intersection
There is no specific name in general. If the line segments are straight, then it is a triangle.
Dihedral angle
DBV
5B
The pubic arch.
Such is called an exterior angle. A useful theorem is that an exterior angle is equal to the sum of its non adjacent interior angles.
That is called an angle.
Right angles aren't formed by other angles - it is already an angle itself. However, if you bisect a right angle, it becomes two acute angles.
It is not an intersection, but the Greenwich observatory in London England.
confluence