Making different shapes

In the latest classes I learnt how to make different shapes using path operathions. I had to try to do it with out even going on to path at the top of the page, I tried it with the clicking Ctrl and then anothor key like the * or the ^ or even simple ones like + and -. My favourite shape is the one with a circle and a triangle that I used difference to make. I put a circle infront of a triangle then I clicked on both objects whilst holding the sift button. Then I clicked on path and then on "difference" that is in the "path box"(the box that comes up when you go over path, on the tool bar at the top of the screen, with your mouse.