Apart from defining the position of the text box, you can also define the dimensions of the entire text box as you like. The text box can be enlarged/reduced from all sides with the help of the arrow buttons located in all the four corners.
You can define the dimensions with help of these arrows with a simple click and drag. All you need to do is select the text box that you want to set the dimensions for, click on any of the arrows and drag the cursor outward to enlarge and drag it inward to reduce.
