how to set margin in latex code example

Example 1: latex page margin

\usepackage{geometry}
 \geometry{
 a4paper,
 total={170mm,257mm},
 left=20mm,
 top=20mm,
 }

Example 2: latex increase bottom margin article class

\usepackage[top=2.75cm, bottom=2.50cm, left=3.00cm, right=2.50cm]{geometry}