To add text to a shape, activate the Pointer tool (the one that looks like an arrow) and double click the shape or directly start typing. An in-place rich text editor for entering/modifying the text of the shape will appear. The buttons in the Font and Paragraph ribbon controls are to format and style the text of the shape. Note that in text edit mode, the text formatting ribbon commands act on the text selected in the rich text editor.

When you have finished entering text, press Escape from the clipboard or click outside of the shape to apply the text change. To cancel the text change and revert to the previous text of the shape, press Shift + Escape.

To add some text to the page, then activate the Text tool (the one that looks like the letter "T"), click and hold somewhere in the page and drag to create a text area. Then, double click inside this text area and enter your text.

 

To format the entire text of a shape at once, select the shape and use the controls in the Font and Paragraph ribbon groups.

To format only parts of a shape's text, double click the shape in order to enter in-place edit mode. Then, select the text to style and use the controls from the ribbon to apply the desired formatting to the selected text.

You can use the copy (the pipette), and apply (the brush), text formatting buttons to copy the text formatting of a shape and apply it to one or more shapes in the same way as for shape geometry.