4:3 
Standard "square" NTSC TV screen-size aspect ratio of 4 arbitrary units wide by 3 arbitrary units high; often expressed as 4x3 or 4 by 3. It was originally known as the Academy Ratio (as in Academy of Motion Picture Arts and Sciences, the film industry organization that awards the Oscars) prior to 1954 and the introduction of wide-screen aspect-ratio film formats; also known in the film world as 1.33:1.