In this paper it is reconsidered the physical meaning of the one-way speed of light, that has also been addressed in other recent papers, complemented with a simple geometric approach. Usually in the standard Special Relativity what is considered is the Einstein one-way speed of light that has been introduced by Einstein in the 1905 article “by definition”. In the standard interpretation the one-way speed of light is not considered since the Einstein speed of light is considered the speed of light. However, in our previous work we have shown that this is a terminological confusion. Now we explain why this is so with a very simple geometric Pythagorean approach that complement recent papers about the same subject. With this approach the measurement of the one-way speed of light and the solution of the conventionality of simultaneity and synchronization controversy is addressed. This proposed formulation is based on the existence of a gap of “synchronizations” with a rod that standard formulation is unable to detect.