Ever wonder why parallel lines never meet?
Parallel postulate
Ever wonder why parallel lines never meet?
Imagine walking straight down a street and noticing two other streets crossing it. If you look at the angles where they cross, they seem to bend away from each other.
Euclid's fifth postulate tells us that if you extend the crossing streets far enough, they'll eventually meet at some point on the same side of the street you're walking on. This idea helps us understand why parallel lines behave the way they do in geometry.
Example
If you extend Street A and Street B, which cross your street at angles less than 90 degrees, they'll meet somewhere down the road.
Remember this
Euclid's fifth postulate explains why parallel lines never intersect if the interior angles on the same side are less than 180 degrees.
Text adapted from Wikipedia, licensed under CC BY-SA 4.0.
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