The image provided shows a geometric configuration with labeled points and segments. Based on the provided information, here's how we can analyze the problem:

From the description, it appears that we are dealing with a triangle and a circle. The following key details are noted:

• $AB$ is tangent to the circle at point $B$.
• The line $EB \parallel DO$.
• Points $O$, $D$, $E$, and $B$ are marked with arrows, possibly indicating certain distances or relationships.

To determine the length of segment $AC$, I'll need to use geometric principles such as properties of tangents, circles, and parallel lines. Let's go step by step.

Approach:

1. Tangents and Radii: Tangents to a circle are perpendicular to the radius at the point of tangency. This means $AB$ is perpendicular to the radius of the circle at point $B$.
2. Parallel Lines: Since $EB \parallel DO$, corresponding angles formed by these parallel lines and other intersecting lines will be equal.

However, there may be some missing information required to make a direct calculation (such as specific distances or relationships between angles). Could you provide any additional details like the lengths of the sides or angles in the diagram? This will help narrow down the solution more effectively.

Let me know if you want to discuss any specific steps or concepts in more detail!