Can I calculate the rotateY angle?

I have to do this

So, can I calculate the rotateY angle in some way or this angle I can define ONLY by eye estimate?

For example, I can do something like this by code below. But as you can see, this is not exactly what I want to do.

.block {
  width: 300px;
  height: 300px;
  transform: perspective(2000px) rotateY(50deg);
  background: #efd9b5;
  border: 1px solid #b95656;
}

<div class="block"></div>