The intake valve seats are in the upper portion of the chamber. Note that (A) shows the single discrete seat angle. It's topped by the chamber and followed up on the downside by the variable radius blend into the port.
(A) also shows the single discrete exhaust seat angle. Note that it disappears in the blend that forms the radius, transitioning into the port. This picture also shows the upper discrete angle (B) that defines the OD of the seat as well as setting up the flow. This discrete top angle blends smoothly into the combustion chamber.