Why is this relevant? How is it used?
Cross section maps typically exaggerate (make bigger) the vertical scale by comparison to the horizontal scale in order to make landforms visible. This exaggeration changes the shape of the map.
A cross section with a bigger vertical exaggeration will be taller on the vertical access than a cross section with a smaller vertical exaggeration.
The answer for VE is just a number (like 5) which means that the vertical scale is 5 times bigger than the horizontal scale.
Calculating
To calculate VE, ie is the vert scale divided by the horizontal scale.
If the vertical scale is 1:40 and the horizontal scale is 1:1000, then the calculation is (1/40) / (1/1000).
Errors
Providing a unit
Putting the scales the wrong way around
More commonly, not having the units the same in the scales
mygeoskills 