Why do vertical properties in percentages won't work?

Question

Like if you set your height of the div to "height: 50%;" it will not work but if you change it to pixels like "height: 250px" it will work.

Answer 1

You can use "vw and vh"
They mean viewpoint's width and viewpoint's height
width: 50vw; is same as width: 50%;

https://code.sololearn.com/W486c884t3Nb/?ref=app