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Sir, Euclid's fifth postulate is considered as a universal fact.Would you briefly explain it and can it be proved with a proof?
If a straight line l falls on two straight lines m and n such that the sum of the interior angles on one side of l is two right angles, then by Euclid’s fifth postulate the lines will not meet on this side of l. Next, we know that the sum of the interior angles on the other side of line l will also be two right angles. Therefore, they will not meet on the other side also. So, the lines m and n never meet and are, therefore, parallel. euclid geometry 17

m || n, If, angle 1 + angle 2 = 180° {i.e. two right angles}

Or, angle 3 + angle 4 = 180°


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