Text Rectangle
Within each shape is a text box that allows for the attaching of text to any given shape. The text rectangle defines where text will reside within the shape. Depending on Auto-fit options that are selected for the body of text attached to this shape the text may intentionally flow outside this text rectangle. It must also be pointed out that this text rectangle will also be the bounding box that is used to compute the geometry of a <prstTxWarp>. The EMU dimensions of this text rectangle will be used to compute this geometry just like the transform extent element is used to compute the actual shape.
The following DrawingML specifies a text rectangle within a shape.
<a:rect l="0" t="0" r="1200000" b="1000000"/>
The text rectangle shown above will have a left edge of 0 x-coordinate, top edge of 0 y-coordinate, right edge of 1200000 x-coordinate and a bottom edge of 1000000 y-coordinate. This will effectively specify a space that is 1200000 EMUs in width and 1000000 EMUs in height.
Note that the edges of this text rectangle can be set so as to allow text to be placed outside the actual geometry of the shape.