RIGHT ANGLES IN NATURE CAN
APPEAR DUE TO GRAVITY, AS A RESULT OF SYMMETRY OF SPACE.
Objects fall under force of
gravity vertically, i.e., perpendicular to the
horizon, which is a level of gravitational equilibrium
(equipotential surface).
Trees grow perpendicular to the
ground
When two
billiard balls collide they
diverge in two directions forming right angle with each
other. Try with coins of equal mass (denominations) on a
table and carefully watch the angle
Right angles appear also in
crystal structures. As a sophisticated example see the
Archimedean
Snub Cube. It has even square
faces.