看下面這張圖檔便一目了然！！！
借助 geometry 包，可以很友善地調整頁面大小，常用的參數如圖所示，這些參數都可以通過LateX支援的機關(mm, cm, pt, in)去重新設定。具體有以下參數：
textwidth Corresponds to element 8 in the figure.
textheight Element 7 in the figure.
total Depends on other parameters, by default defines the dimensions of the Body, but can be combined with the includehead, includefoot, includeheadfoot and includemp commands to change the dimensions of Header, the Body, the Footer and the Margin Notes altogether.
left, lmargin, inner These three parameters change the length of the left margin. Elements 1 and 3 in the figure, combined.
right, rmargin, outer These three parameters change the length of the right margin. Elements 9 and 10 in the figure, combined.
top, tmargin These two parameters represent elements 2 and 6 in the figure, combined.
bottom, bmargin