Geometric decorative style (3,4)
I believe the answer is:
art deco
(Other definitions for art deco that I've seen before include "pre-war style" , "Architecture and design movement of the 1920s and 30s" , "1920s and 1930s ornamental style" , "1920s and 1930s style of ornamentation" , "Architecture/design movement of the 1920s and 30s" .)