6m by 5m by 4m , rectangular tank

How do you know which one is the height?

You don't.

To determine which dimension represents the height of a rectangular tank, you can utilize the fact that the height usually corresponds to the vertical dimension of the object. In this case, consider the given measurements: 6m by 5m by 4m.

To identify the height, follow these steps:

1. Visualize the rectangular tank: Imagine the tank in your mind or draw it on a piece of paper. Pay attention to its shape and orientation.
2. Analyze the given measurements: Look at the dimensions provided, i.e., 6m, 5m, and 4m. Imagine the tank based on these values.
3. Observe the tank's shape and orientation: Determine which side of the tank appears to be the vertical side, perpendicular to the ground. This side would represent the height of the tank.
4. Consider common conventions: In general, height is often referred to as the vertical dimension or the measurement that extends upwards from the base. This is a common convention for rectangular objects.

By using these steps, you should be able to identify which dimension represents the height of the rectangular tank.