Greenbelt Theatre, which anchored GREENBELT CENTER. Although conceived and built as a moving picture venue, it was dedicated with an evening of live performances on May 6, 1938.
Photo from Library of Congress / Marion Post Wolcott

The first movie shown at the new cinema was Shirley Temple's "Little Miss Broadway," which started its Greenbelt run in September 1938. At that time, an adult ticket went for 25 cents, with a children's admission costing 15.   
Graphic from Wikipedia / "MovieMadness"

Coming attractions at the Greenbelt Theatre, in July 1939. As the ad attests, the cinema is now air-conditioned. 

Advert from The Greenbelt Cooperator / Library of Congress