What explains the symmetrical arrangement of the belts relative to the equator?

The distribution of heat and, accordingly, the distribution of climatic zones is influenced by the spherical shape of the Earth. This is due to the fact that the further the territory is from the equator, the greater the angle of incidence of the sun’s rays. Those. from the surface, some of the rays are reflected back into space. Since the equator passes in the center of the planet, the angle changes evenly to the north and south of it, therefore the climatic zones are evenly distributed. At latitudes close to the equator, the sun’s rays fall almost at right angles, as a result of which there is no change of seasons and the climate is stable.