And so given everything that we've set up right over here, the question is, at what rate is the shadow moving? So let's think about what we know and what we don't know. And to do that, let's set up some variables. So let me draw the same thing a little bit more geometrically. So let's say that this right over here is the street light that is 20 feet tall. And then this right over here is the height of the owl right at this moment. So this is 15 feet.