Euclid's parallel postulate.
Probably the best known equivalent of Euclid's parallel postulate, contingent on his other postulates, is Playfair's axiom, named after the Scottish mathematician John Playfair, which states:In a plane, given a line and a point not on it, at most one line parallel to the given line can be drawn through the point.
The short form of Euclid's 5th postulate, also known as the parallel postulate, states that if a line intersects two other lines and creates interior angles on the same side that sum to less than two right angles, then the two lines will intersect on that side if extended. In simpler terms, it implies that through a point not on a given line, there is exactly one line parallel to the given line. This postulate is fundamental in distinguishing Euclidean geometry from non-Euclidean geometries.
... given line. This is one version of Euclid's fifth postulate, also known as the Parallel Postulate. It is quite possible to construct consistent systems of geometry where this postulate is negated - either many parallel lines or none.
Yes they are. It is delineated in something called the parallel postulate, and the axiom is also called Euclid's fifth postulate. This is boilerplate Euclidean geometry, and a link can be found below if you'd like to review the particulars.
There are only five recognized Euclid postulates.
No.
It is NOT considered a universal truth. It used to be, because mathematicians considered it to be "self-evident", but more recently, mathematical systems both with and without the parallel axiom have been developed. It turns out the "non-euclidian geometries" are very useful. In the real world, the euclidian geometry does NOT apply - although in many cases it is a good approximation.
Euclid’s Elements
Euclid's second postulate allows that line segment to be extended farther in that same direction, so that it can reach any required distance. This could result in an infinitely long line.
A straight line segment can be drawn joining any two points.
It is proven by a theorem (which relies on Euclid's parallel postulate).
Yes by one definition of interior angles - it does !
It is a consequence of Euclid's parallel postulate. In fact, in some versions, the statement that "a plane triangle has interior angles that sum to 180 degrees" replaces the parallel postulate.
Euclid's parallel postulate.
That is only true of triangles and is a consequence of the parallel postulate. In fact it is an alternative way of stating Euclid's parallel postulate.
It is a consequence of Euclid's parallel postulate.