change br height

1// Use this instead of <br> so you can use css to change height:
2/* The best spacer ever invented */
3hr.space-1 {
4  background: transparent;
5  color: transparent;
6  margin: 0;
7  border-style: none;
8  height: 1vw;
9}
10<hr class="space-1">

1/*Search Term: "CSS change image height"*/
2
3img {
4  height: /*Add height here*/;
5}
6
7/*Example*/
8img {
9  height: 200px;
10}

1You can't change the height of the br tag itself, as it's not an element that takes up space in the page. It's just an instruction to create a new line.
2
3You can change the line height using the line-height style. That will change the distance between the text blocks that you have separated by empty lines, but natually also the distance between lines in a text block.
4
5For completeness: Text blocks in HTML is usually done using the p tag around text blocks. That way you can control the line height inside the p tag, and also the spacing between the p tags.
6
7