More sophisticated layouts can be created using the Section, Column and Panel macros. To add a macro, when editing a page go to Insert, choose Other Macros... and type in the name of the macro. Select the icon and insert it. When editing complex layouts, you may find it easier to use Wiki Markup view instead of Rich Text.
The section macro defines an area which can contain columns.
The column macro subdivides a section. You have have multiple columns in a section, using the width setting to size them. You must use column macros within a section macro.
A second 50% width column.