Which of the following is not one of the five parts of a terrain sketch?

A terrain sketch is an essential tool used in military operations for effective planning and execution, particularly in Fire Support Team (FIST) operations. The five recognized components of a terrain sketch typically include natural and manmade features, which aid in visualizing and understanding the operational environment.

Manmade features encompass identifiable structures and infrastructures that can impact military operations. Understanding these allows tactical units to leverage or avoid these elements during planning or combat.

Skyline includes the visible contours and highest points in the terrain, aiding in determining potential line-of-sight and cover opportunities.

Intermediate crests, hills, and ridges refer to important terrain features that can impact movement and visibility. Recognizing these features allows for strategic positioning and use of cover in operations.

Complex terrains, while they may represent a type of geographical area, are not classified as a distinct part of a terrain sketch. Instead, they may fall under the broader categories of natural features or specific elements within the other recognized parts, which emphasize clarity and graphical representation in operational contexts.

Thus, the correct identification of complex terrains not being part of the traditional five parts highlights the distinction between generic geographic features and the specific components necessary for effective terrain sketches in military operations.