4. What happens to the horizontal rule line when you increase the width size number?

When you increase the width size number of a horizontal rule line in HTML, the line becomes wider. The width attribute specifies the width of an element, and in the case of a horizontal rule line, it determines how much horizontal space the line occupies on the page.For example, if you set the width to "100px", the horizontal rule line will occupy 100 pixels of horizontal space on the page. If you increase the width size number, the horizontal rule line will occupy more horizontal space, making it wider.It's important to note that the width attribute can also be set to a percentage value, such as "50%". In this case, the horizontal rule line will occupy 50% of the available horizontal space on the page.