Consider the following code and output.
\documentclass{article}
\usepackage{lipsum}
\usepackage{graphicx}
\usepackage{wrapfig}
\begin{document}
\begin{wrapfigure}{o}{0.5\textwidth}
\centering
\includegraphics[width=2in]{image.png}
\end{wrapfigure}
\noindent\lipsum[1]
\end{document}

How can I have the text follow the gradient of the triangle in the image?

\parshapeprimitive can handle this. – Werner Jun 11 '13 at 22:51\parshapeprocedures laid out in any of the above, linked questions. Have you tried it? – Werner Jun 11 '13 at 23:05