system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are conifers usually triangular while deciduous trees are usually 'circular' in profile?
gpt
Conifers tend to be triangular because they don't drop their needles and often live in snowy places. The triangle shape holds up best to the added weight. Plus it's efficient in terms of how much energy has be spent on growing a trunk, and again, they live in colder places with less competition.

Deciduous trees are rounder because they want to grow up and out to shade out their competition, and they drop leaves so added winter weight is not a problem.