Anet for a cylindrr object will consist of which shapes

think about it this way

a cylinder will be like a soda can, so  you get an empty soda can, if you cut the circular top and bottom, you end up with ⃝ and ⃝.

then if you with a knife cut the leftover vertically and lay it flat, you're left with ▯.

so the soda can was really just

the easiest way to do these would be to solve the equations. if you can solve the equation than you can solve these problems.

1/4 is the answer if i recall correctly.