Final answer:
In context to HTML, 'size,' 'color,' and 'width' are attributes that have been or can be used in tags, while 'length' is not a standalone attribute in HTML; the concept of length is expressed via other dimensional attributes like 'width' and 'height'.
Step-by-step explanation:
The question 'Which attribute does not come in a tag?' refers to the attributes used in HTML (Hypertext Markup Language) for formatting web pages. Let's evaluate the options provided:
- Size: While not commonly used in modern HTML and CSS, 'size' has been used in the past as an attribute for elements like <font>.
- Color: 'Color' can be used in HTML, usually as a part of the 'style' attribute to alter the color of text, backgrounds, etc.
- Width: 'Width' is a valid attribute and is often used to specify the width of elements like images and tables.
- Length: 'Length' is not a standalone attribute in HTML. The concept of length is controlled by other attributes like 'width' and 'height' for various elements.
In conclusion, the attribute length does not come in a tag.