To shape molding, the radial-arm saw blade must be angled to make a cove cut. To do that, swivel the blade to the desired angle, less than 90 degrees.
Lower the blade onto the stock and lock it in place.
Slowly run the stock through, parallel to the rip fence. The wider the angle of the blade, the steeper the cove cut will be. Cut compound coves using the same technique with multiple passes.