Using this tab, you can modify the settings of the text in your dimension. The first panel, Text appearance, will help you change the appearance of text:

You can change the text style using the Text style dropdown. If you want to modify the text settings, then click on the ellipses next to the Text style drop-down menu, as shown in the following screenshot, and the Text style window will open where you can modify text settings further:

You can change the color of text using the Text color option and the background color of the text can be changed using the Fill color option. The height of the text is the next field, called Text height.

When you have changed the arrow size on the Symbols and Arrows tab, then it is recommended to change the text size as well to the same value, so that both remain consistent. Click on Draw frame around text to enclose the dimension text in a box.

The second panel, called Text placement, will change the placement of your text on the dimension or extension lines. Change the options in this panel to move the dimension text around. The third panel, Text alignment, has three options: Horizontal, which makes the dimension text horizontal with respect to drawing; then the second option, Aligned with dimension line, aligns the dimension text with the alignment of the dimension line; and finally, ISO standard, which will align dimension text as per ISO standards.