\documentclass[12pt]{article}
\usepackage[latin1]{inputenc}
\def\ratio#1#2{\frac{\overline{#1}}{\overline{#2}}}
\newtheorem{geothm}{Theorem}
\pagestyle{empty}
\addtolength{\textwidth}{2cm}
\begin{document}
\large
\begin{geothm}[Ceva's Theorem] 
Let $\Delta ABC$ be a triangle and $P$ be any point in the plane. Let $D=AP\cap CB$, $E=BP\cap AC$, and $F=CP\cap AB$. Show that:

$$
\frac{\overline{AF}}{\overline{FB}} \times \frac{\overline{BD}}{\overline{DC}} \times \frac{\overline{CE}}{\overline{EA}} = 1
$$
$P$ should not be in the lines parallels to AC, AB and BC and passing  through B, C and A respectively.
\end{geothm}
nd{document}
