A coworker just approached for make to make his wife's birthday cake. She is part of the Delta Sigma Theta sorority.

He is cake clueless and the only thing he said was three things:
*Triangle Shaped
*Red and White
*and use a lady figure that's one of the sorority (delta sigma theta) symbols: http://www.dartmouth.edu/~dst/fortitude.jpg

He doesn't want a plain cake, what else could I do with it to make it girly and birthday like?
Also, I do not have a triangle pan and was thinking about using a square pan and carve it to shape. This cake should feed 20 people. How big should be triangle be?

Any help would be greatly appreciated!