Get the height of a div without Jquery

I need to set the height of the based on the height of the ion-slide.

So the height of the ion-slide-box depends whether I am on slide 1 or 2 or 3 etc.
That's why I can't do it with CSS. I just can't.

But to get back on track, is there really no way to get the height of a div using angular / ionic ??