Euclid's postulates are:
Axiom 5.1- Things which are equal to the same thing are equal to one another.
Axiom 5.2 - If equals are added to equals, the wholes are equal.
Axiom 5.3 - If equals are subtracted from equals, the remainders are equal.
Axiom 5.4 - Things which coincide with one another are equal to one another.
Axiom 5.5 - The whole is greater than the part.