ckeating08

This is probably something simple, but it is driving me insane. Somehow my finder is too big for my monitor. I don't have any idea how it happened. I am relatively new to mac, so bare with me. I have tried everything to fix this. I went to system preferences, then to display and the only thing that I see there is resolution and color controls. I have looked on other forums and then mentioned that there should be a geometry control under display, but I do not have one. All that I need to do is adjust the height and width of my finder. But have not been able to figure out how to adjust it. Please help