How to display an RSS feed widget inside a page?

by

if you know php you could add it to a template using
wp function http://codex.wordpress.org/Function_Reference/the_widget

or there is wp code to pull in a feed and list it
http://codex.wordpress.org/Function_Reference/fetch_feed

if you want a non coding solution, there are some plugins like:

http://webdesign.anmari.com/1649/shortcode-any-widget/