In the given figure, AB is a chief of a circle and AOC is its diameter such that ACB = 50°. If AT is the tangent to the circle at point A, then find BAT.

In the figure angle CBA = 90 degree because angle in a semicircle is of 90 degree
so by ASP of triangle angle CAB = 40 degree      ---(180-(90+50)
now angle OAT is 90 degree because angle between radius and tangent is of 90 degree
So angle OAB + angle BAT = angle OAT 
40 + angle BAT = 90
angle BAT = 50 degree
Hope u got it!!