Sentence:  Just as the pressure exerted by surface tension in a spherical <WSD>drop</WSD> is * * f and the pressure exerted by surface tension on a cylindrical shape is * * f , the pressure exerted by any curved surface is * * f , where |g is the interfacial tension and * * f and * * f are the two radii of curvature . 
Meaning of the word marked with <WSD> tags:  a shape that is spherical and small