Triangular versus normal distribution?

Question

Why should a triangular distribution be used when looking at the relative risk of mortality for 2 disease phases instead of a normal distribution?

Answer 1

The Triangular Distribution is typically used as a subjective description of a population for which there is only limited sample data, and especially in cases where the relationship between variables is known but data is scarce (possibly because of the high cost of collection). It is based on a knowledge of the minimum and maximum and an "inspired guess" as to the modal value.
---
So, my guess would be that you know the extremes (min and max) but have only a guess as to the mode... Therefore you wouldn't be able to use a normal distribution since you'd need to know the mean value and you'd be basing that on a guess.