My Angry Issues.

I have always had anger issues and I take most things to heart so a lot of things make me angry. I used to express those emotions all the time but I am trying to become more understand and be nicer. Well in my class I couldn't take it and I think I might of made it worse for me. For some reason I feel like my instructor doesn't like me very much and he says a lot of things to me that really do not make sense. Well I kind of went off on him. I will explain. I have to do discussion questions its pretty normal with online school.
The question I had to answer was this:Using examples, describe the difference between depth and volume. Is it possible to have a sense of volume without a sense of depth? And conversely, is it possible to have a sense of depth without a sense of volume?
My responds: The difference between depth and volume is volume is capacity and depth is length. For example; if you look at a square box volume would be the space inside the box and depth would be how far the box went back. It is impossible to have a sense of volume without depth because depth is what makes up the volume. You can however have depth and not volume if you do not think about what is in the depth.
It was very simple but get the question answered.
My instructor says:Your answer is simple, perhaps a bit too simple. I would like you to describe the difference between depth and volume again. What you have written is correct, but not too clear. Think about trying to explain the difference to a class room of 1st graders or someone who has no artistic understanding. Really break it down and explain depth and volume with examples so anyone can understand.
What? Seriously? How freakin complicated do think this subject is? I get stuff like this all the time and ignore it because I think its stupid well this time I couldn't
I responded: I really do not understand what you are saying. Yes my answer is simple but it explains what depth and volume is and there really isn't much to it. If I was explaining it to a class room of 1st graders I would still do it the same. I work with kids every Sunday and I have one of my own and know they do not have much of an attention span so I would get the point a cross as quick and simple as I could, which I did. Also if I wanted to explain it to someone with no artistic understanding I think this would work. Even with out artistic understanding I think everyone knows what a square box is. I know I will probably loose points for this but I do not know what to say. Depth and volume is not a hard concept to understand.
I probably took it to far and I probably shouldn't of done that but oh well can't take it back now. I guess I am not getting an A in this class!