Question

Identify which of the given plan views (nets) can be folded to make the 3D object shown (a short cylinder with a tall, thin rectangular slab attached on its circular top and extending upward). 

• A. Net A
• B. Net B
• C. Net C
• D. Net D

Hint:

When testing a net for a “wrap + fin” solid, imagine rolling the wrap first. Any part meant to become a vertical fin on the top must hinge from the wrap’s top long edge, not a short edge or the vertical seam.

Answer 1

The Correct Option is A, C

Target solid: A short right circular cylinder (curved wrap $+$ circular base), with a tall, thin rectangular slab standing on the cylinder’s top circle along a diameter.
What a correct net must have:
One curved wrap (a rectangle) that becomes the cylinder’s lateral surface.
One circular base attached to a long edge of the wrap (to close the bottom).
A circular top is not separate here—the top is occupied by the slab; thus we need either:
(i) a second circle with a slit/tab to accept the slab; or
(ii) the slab attached directly to the wrap so that, when folded, it lands across the top circle like a fin.
The tall slab must hinge from the correct edge so it stands on the top circle without intersecting the side wall or hanging off.
Check the options:
(A) The slab is attached opposite the base circle along the wrap’s top long edge; upon rolling the wrap and fixing the base, the slab folds up to sit on the top circle—works.
(B) The slab connects from a short side; after rolling the wrap, its hinge lands on the cylinder’s vertical seam, making the slab hang off the side—does not work.
(C) Like (A), the slab is placed to hinge across the top circle after the wrap is rolled—works. (D) The slab’s hinge is misaligned (offset), so when rolled it cannot lie across the top circle—does not work.
Therefore the feasible nets are \(\boxed{\text{A and C}}\).