Aspect ratio of main frame of beamer is not changing to 16:9

Question

I am new to beamer, and unfortunately, I am getting aspect ratio problem. I am working with beamer template warsaw by Till Tantau. It is working fine but I would like to use the landscape orientation. For that, I changed the aspect ratio in document settings--document class--custom--aspectratio=169, ,10pt. and I am using these packagers in the preamble;

\usepackage[orientation=landscape,size=custom,width=16,height=9,scale=0.5,debug]{beamerposter} %%%%self for aspect ratio

\usepackage{bookmark}

\hypersetup{bookmarksdepth=4,bookmarksnumbered=true,bookmarksopen=true}

\setcounter{tocdepth}{1}
% or ...

\setbeamercovered{transparent}
% or whatever (possibly just delete it)

%\usepackage{palatino}%
\usepackage[sc]{mathpazo}
\beamertemplatenavigationsymbolsempty

%Set Presentation mode and colors
%--------------------------------------------------------
\mode<presentation> {
  \setbeamertemplate{background canvas}[vertical shading][bottom=white,top=white]
  \usetheme{Warsaw}
  \usefonttheme[onlysmall]{structurebold}
 % default | professionalfonts | serif |
 %    structurebold | structureitalicserif |
 %    structuresmallcapsserif
}
\setbeamertemplate{navigation symbols}{}%remove navigation symbols

%Using packages
%--------------------------------------------------------
\usepackage{amsfonts}\usepackage{amsxtra}\usepackage{pgf}
%\usepackage{german} %%I changed it
\usepackage{graphicx}
\usepackage{float}
\usepackage{multirow}
\usepackage{units}
%\usepackage{multimedia}
\usepackage{color}
\usepackage{colortbl}
\usepackage{booktabs}
\usepackage{hyphenat}
\usepackage{movie15}
\graphicspath{{./picture/}}
\include{defs}
\usepackage{animate}


%Begin of the document
%--------------------------------------------------------

\setbeamertemplate{frametitle}[default][left] %%for setting frame titles to the left

%%to change font size
%\usepackage{scrextend}
%\changefontsizes{10pt}

Now the problem is it is changing the aspect ratio of body text not the frame. Here is the example picture;

Answer 1

I believe that landscape orientation need to be applied by using following command:

% lscape.sty Produce landscape pages in a (mainly) portrait document.

\usepackage{lscape} ... \begin{landscape} ... \end{landscape}

You may refer to following articles: How to change certain pages into landscape/portrait mode

Answer 2

To control the aspect ratio and also size of the presentation, you only have to use:

\geometry{paperheight=<whatever>,paperwidth=<whatever>}

Decreasing the paper dimensions you can have a (relatively) larger font or viceversa, so ideally you do not need even to touch the default font settings.

MWE:

\documentclass{beamer}
\usetheme{Warsaw}
\geometry{paperheight=4.5cm,paperwidth=8cm}
\begin{document}
\begin{frame}{foo}
foo 
\end{frame} 
\end{document}