Stealth is relative, even IR detectability is relative...
If you are behind an F-22 on full burners, you will be more likely to detect him (and from longer range) then when the Raptor is on Cruise setting.
Also, with radar, you will be more likely to detect him from some angles then from other angles (ie. front will have lesser RCS then bottom, just because front has smaller surface then bottom).
EDIT: About the triangles and rectangles: in cockpit it looks like this, but i still don't know what's its function Cockpit
And this discussion about PAK FA vs. F-22... What's the point?? ... Cold war is over...
IMHO, PAK FA and F22 will never dogfight eachother or even fight eachother...