Flat, or flatness, describes an object or condition that is very smooth or level.In Great Britain, Ireland and Australia, as well as in English spoken in Commonwealth countries such as India, a "flat" means an apartment.
A pinnacle (from Latinpinnaculum, a little feather, pinna, compare panache) is an architectural ornament originally forming the cap or crown of a buttress or small turret, but afterwards used on at the corners of and in many other situations. The pinnacle looks like a small spire. It was mainly used in Gothic architecture.