He knew that a stick stuck in the ground in Alexandria at the same time and the same day, at noon, the sun's zenith, on the solstice, the sun cast a shadow that showed that it was 7.2 degrees off-axis.
no mesmo dia e hora , ao meio-dia, o zenite do sol no solsticio o sol fazia uma sombra que se mostrava 7,2 graus fora do eixo.