Final answer:
Ernest Flagg's architectural style can be categorized as a combination of Art Deco and Streamline Moderne.
Step-by-step explanation:
Ernest Flagg was an American architect known for his contributions to the Art Deco and Streamline Moderne architectural styles. Art Deco emerged in the 1920s and combined traditional craft motifs with Machine Age imagery and materials. On the other hand, Streamline Moderne was a late type of the Art Deco style that emerged in the 1930s, emphasizing curving forms, long horizontal lines, and sometimes nautical elements.
Ernest Flagg's architectural style can be categorized as a combination of Art Deco and Streamline Moderne. He incorporated elements from both styles, such as the bold geometric forms and heavy ornamentation of Art Deco, as well as the aerodynamic curves and horizontal lines of Streamline Moderne.