Question

I found this answer on the Internet. *If* it were an original answer, below is how I would grade it and why.

Answer 1

Answer:

1) It is given that line AB is tangent to the circle at A.

∴ ∠CAB = 90º (Tangent at any point of a circle is perpendicular to the radius throught the point of contact)

Thus, the measure of ∠CAB is 90º.