AC is tangent to circle
at point C
What is the measure of ACO?
                                             
                                          
                                          
                                        
											 
											Answer:
∠ ACO = 90°
Step-by-step explanation:
The angle between a tangent and a radius at the point of contact is 90°
Thus the angle between AC and OC is ∠ ACO = 90°