The Canvas Rich Content Editor doesn't have any tools that will allow you to create hanging indents automatically in Content Pages, Assignments, Quizzes, Discussions, etc. If you want to format a hanging indent, you'll need to switch to the HTML Editor to customize the code. Instructions are here: Hanging Indents: code-snippet
<p style="margin-left: 20px; text-indent: -20px;">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed placerat accumsan viverra.</p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed placerat accumsan viverra. Nam faucibus suscipit nunc vitae iaculis. Morbi in pretium leo. Integer fermentum at tortor et dapibus. Aliquam quam magna, mollis sed leo at, pretium auctor nulla. Vestibulum ac est eu mi aliquet ultricies. Phasellus condimentum tristique mi, eu aliquet metus tincidunt quis. Duis egestas blandit nunc, eu lacinia ex cursus ut. Vivamus rhoncus ipsum orci, in gravida dui pretium id. Vivamus a justo consequat, laoreet lectus ut, scelerisque lacus. Interdum et malesuada fames ac ante ipsum primis in faucibus. Pellentesque et augue eget nisl semper volutpat sed ut urna. Aliquam id gravida felis.