Property of a tangent

We can see a circle in black color with center A. There is a point B on the circumference of the circle. Two lines are drawn, ‘a’ is passing through both the points A and B and ‘b’ is a tangent to the circle at point B. We can freely move these two points A and B. Observe how the positions of lines and circle change as we move the points A and B. Angle between the lines ‘a’ and ‘b’ is also written
Questions to think about 1. Is it possible to have angle α≠90˚?