(I can't do the nets but ya know oof if I figure out how I'll post it to ya)
Ok, so the volume formula is the area of the base x the area of the height.
The triangles area is 12(3x4), and the area of the prism is 4(2x4(The base of the triangle is also the base of the prism).
12 x 4 is 48, so the volume is 48.
Ok, for the surface area we add 12+12+4+4+4, and that would be 36, so the sa is 36.
Now, For The other question, the diameter is 12, and the volume formula for a cylinder is V=πr2h . So, the radius is half the diameter so 12 would turn into 6, and when you put the height and radius into the formula along with pi it would turn out to be 791.68.
The area of a circle would be πr2. So the area would be 113.1.
The circumference of the circle(The length of the base of the cylinder) would be 2πr, and that would be 37.7. So the area of that is 37.7.
Now, we add 113.1+113.1+37.7 and it would be 263.9. So the surface area of that is 263.9
(Now listen, I honestly tried my best. If I messed up, please tell me where and I will correct my mistake)
