good geo program?

[catboy17]

Hi. I've been looking for a good geo program and I haven't found quite what I'm looking for. I want something that will give me things like area, surface area and volume for different shapes like circles, cylinders, spheres etc. Geometry Formulas Plus and others like it are the best I've found so far. The problem is that I also would like to be able to calculate, say, a height based on knowing all of the other variables, including the area or what have you. These programs will only let me get out the area/volume, not let me put it in. In my favorite triangle program, ProSolve, I'm able to put in a 0 for the value I don't know, so if I know the area I can put in a zero for the value that I want. Putting in an x or blank would be fine too. I was just wondering if anybody knows of a area/volume kind of program for various 2d and 3d shapes that would work similarly. Thanks.

[bluesuit]

you could use the equation and plug in known numbers and use the solve function.