I'm not quite certain what "draw a net" means here. But for part b, we are doing the formula. The bottom part is a square(assumingly so take this with a grain of salt), thus making the base equal to 3*3 cm or 9 cm^2. The triangular faces are each 3*2.24 cm or 6.72 cm^2. We then multiply this by 4 to get 26.88. Thus, the equation is Bl^2(Base length squared)+Bl*Fh(Face height, I forgot the official name sorry about that)*4 for part b.
Ah hah ! You said in there "race AGAIN". Tell us something about how the first race turned out, and we may have some information we can use to answer with. Right now we got nuttn.