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.
