What is the rate of change of the angle, theta of t between the ground and the ladder at that instant? What I'm gonna do is draw this out, and really the first step is to think about, well, what equation will be helpful for us to solve this problem? Then we might just go ahead and actually solve the problem. A 20 meter ladder is leaning against a wall. Let me draw ourselves a wall here. That is my wall. Now let me draw our 20 meter ladder.