A valley carved by a stream in high mountains typically has the shape of a V-shape.

Here's why:

* Erosion: The stream's flowing water erodes the rock and soil at the bottom of the valley, carving a deeper and deeper channel.

* Steep Sides: The steep sides of the valley are formed by the erosion of the surrounding mountains.

* Narrow Bottom: The bottom of the valley is narrow because it's primarily carved by the stream's flow.

This V-shape is a characteristic feature of young, actively eroding valleys found in mountainous regions.