Here is how you will REALLY use your geometry knowledge...
You will determine that you can make TWO dome-shaped teacups from a balloon covered with paper mache if you cut it with a hack-saw when it's dry.
You will realize that you need to add a slice of a cylinder on each side of the balloon so that each of the two teacups stands up nicely. Unless your going for the Japanese sake-type teacup, you'll add a handle on each cup, and I think that has nothing to do with geometry.
You will see the correlation between an overinflated balloon and a teapot, if you stand the balloon on its fat end. The knot in the balloon will actually remind you of the knob on the top of the teapot's lid, so you'll take that as a cue to add a nice knob on the top, in addition to the aforementioned cylinder (ala the teacup - for stability) and even if you didn't take calculus or study black holes, you'll be able to make a spout, curve it nicely, and attach it to your balloon. Hey, who needs that much math unless you're going to become a scientist?
You'll sand the little devils quickly so they don't look gnarley (is that even a real word?) for your fancy-pants tea party. You'll learn all about sanding in your Technology class - back in the day (I hate that phrase) we used to call it Shop.
After you've decided on the table linens, you'll paint them (tomorrow) and enjoy a nice cup of imaginary tea. Bon apetite!