what is meant by, ‘solving Euclid’s 5th postulate’.

813 views

As someone who failed his algebra 1 final twice and geometry once, can someone explain to me what is meant be “proving” Euclid’s postulate five? Like, the point of the postulate is two lines that cross another line will, at some point, meet if they’re angled toward each other. I get that.

What I don’t understand is why that needs to be ‘solved’ or ‘proven’. What were so many mathematicians trying to do? How would they go about ‘completing’ it? Why did it need to be completed?

In: Mathematics

7 Answers

Anonymous 0 Comments

Euclid’s fifth postulate has not been proven, it has to fall back on the parallel lines postulate for its utility. Because it is possible to create entirely self-consistent, non-Euclidean geometries where the parallel postulate doesn’t hold, that means that it’s possible that the 5th *might* not hold even in the Euclidean geometry. Proving it true or false would mean that the rest of the geometry would be more or less reliable.

You are viewing 1 out of 7 answers, click here to view all answers.