Beamer分辨率，页面宽度，页面长度，页面大小

By default, the size of the beamer slides is 126 mm by 96 mm, which corresponds to a 4:3 aspect ratio. However, the document option aspectratio lets us change this ratio. The values that it accepts are: 1610, 169, 149, 54, 43 and 32, which stand for the ratios 16:10, 16:9, 14:9, 5:4, 4:3 and 3:2, respectively.