Which stockpile shape is defined as a tent-shaped pile built using a radical or movable stacker?

The tent-shaped pile described in the question is accurately characterized by its ability to be formed using a radical or movable stacker, which typically has a sloped appearance. This design allows for efficient management of the stockpile, maximizing the use of space while improving material flow.

In contrast to other shapes mentioned, the elongated cone has a distinct profile that tapers gradually, creating a more elongated form rather than a steep tent shape. This configuration can often enhance drainage and reduce compaction issues, making it more conducive for certain aggregate types.

The cylindrical stack is characterized by a uniform, round profile, distinctly different from the cone shapes. While it offers some advantages in terms of stability and ease of construction, it does not match the specific tent-like appearance noted in the question.

A flat pile, on the other hand, consists of a broad, horizontal surface without the defined elevation changes seen in cone structures. While flat piles may be easier to manage and control, they lack the height and shape associated with tent-shaped piles.

Thus, the elongated cone stands out as the option that accurately reflects the tent-like characteristics described in the question.