Final answer:
The measure of AC cannot be determined without further context or information. More details are required to provide an accurate answer.
Step-by-step explanation:
The measure of AC is not provided with enough context or information in the question you've asked, making it impossible to determine the answer. It's possible that AC refers to a line segment or angle in geometry, but without specific details, such as a diagram or description of a figure, no accurate answer can be given. Please provide additional information, such as relationship to other angles, position within a particular shape or figure, or any given equations relevant to the problem at hand.