Answer :

Final answer:

In web design, 'em' is a unit proportional to the current font size. If the base font size is 12 pixels, then '3em' would be three times that, or 36 pixels.

Explanation:

In CSS, the measurement 'em' is a scalable unit that is used in web document media. It is equal to the current font size. For instance, if the base or current font size is 12 pixels, then '1em' is equal to 12 pixels. Therefore, if you set a tag to be '3em', that would mean it's set to be three times the base font size. So, in this scenario, an 'tag' set to '3em' would be equivalent to 36 pixels.

Learn more about CSS Measurement Units here:

https://brainly.com/question/33719822

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