Read the following statements which are taken as axioms:
Is this system of axioms consistent? Justify your answer.
Given the system of axioms is not consistent.
Solution:
Axiom: A statement or proposition which is regarded as being self-obviously evident, established or accepted. Hence, it is accepted without controversy or question.
Statement (i) is False.
We know that if a transversal intersects two parallel lines, then each pair of corresponding angles is equal. It is a theorem.
Theorem: A statement or proposition not plainly obvious but rather demonstrated by a chain of reasons; a fact set up by methods for acknowledged certainties
Statement (ii) is true.
If a transversal intersects two parallel lines, then each pair of alternate interior angles are equal. It is also a theorem.
In the given figure, 3 = 6, 4 = 5 (alternate interior)
1 = 5, 2 = 6, (corresponding angles)
3 = 7, 4 = 8 (corresponding angles)
Hence statement (i) is not an axiom.
Statement (ii) is true and an axiom
Hence, the given system of axioms is not consistent.