I am having a xib where I have added a UIView as subview to the main view. I want this subview to be of a proportionate height to the main view. But there is no 'Equals Height' option to do it. I would have been able to do this had it been a view controller in a storyboard.

![enter image description here](https://i.stack.imgur.com/sciOo.png)

So how to achieve a constraint where the subview's height is a ratio of superview's height (say 3:4).