To find x in the circular sector problem, the arc-length formula \( s = r\theta \) can be applied to derive two equations involving x and the angle \( \theta \). Additionally, the concept of similarity can be utilized to establish a ratio between the radius and arc-length for the sectors. This approach allows for the formulation of equations that can help solve for the unknown variable x. Both methods provide a structured way to tackle the problem using trigonometric principles. Understanding these relationships is key to finding the solution effectively.