PQRS is a trapezium and ORS is an isosceles triangle. In an isosceles triangle, base angles are equal.<br><br>From the figure, the base angles of the isosceles triangle ORS are each 57.5&deg;.<br>Using triangle angle sum: \(\angle ROS = 180&deg; - 57.5&deg; - 57.5&deg; = 65&deg;\).<br><br>Final Answer: 65&deg;