In the detailed view, you can add rectangles and ellipses to pages by clicking on the relevant shape in the sidebar next to the page.

Example: rectangle

En cliquant sur le rectangle, tu actives le ruban d'édition. Tu peux effectuer les actions suivantes: 

• Change the colour
  • You can choose any colour using the colour picker, the eyedropper, or a hexadecimal or RGB code
• Change the opacity / transparency
• Add a border
  • Clicking on the border expands the existing ribbon.
  • You can remove the border from the rectangle by entering 0 here
• Round the corners
• Edit layers
• Delete