Have you looked at this sample? http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#IntersectWhen the Intersect is completed, you can get the vertices in your geometry. These are your intersection points.I think another way is to do the following (assuming you are working with polygon):
if (first.Geometry.Extent.Intersects(second.Geometry.Extent))
{
PointCollection pc = new PointCollection(); // will contain all intersection points
foreach (var p in (first.Geometry as Polygon).Rings)
{
for (int i = 0; i < p.Count; i++)
if (p.Extent.Intersects(second.Geometry.Extent))
pc.Add(p.Clone());
}
}
The intersection in the above code checks against geometry extent though. So maybe you need to get the polylines formed by the vertices and check intersection against these polyline extent.
