Question

Which of the following statements is not a Euclid’s axiom?

• A. If equals are added to equals, then the wholes are equal
• B. The whole is greater than the part
• C. All right angles are equal to one another
• D. Things which are double of the same thing are equal to one another

Answer 1

The correct option is C All right angles are equal to one another

The term ‘postulate’ was used by Euclid for the assumptions that were specific to Geometry only. Axioms, on the other hand, were assumptions used throughout Mathematics and not specifically linked to Geometry.
Thus, “All right angles are equal to one another” is one of Euclid’s postulates but is not a Euclid’s axiom.
Hence, the correct answer is option (c).