Question

Which undefined terms are needed to define parallel lines?

Point, line
Line, plane
Coplanar, line
Point, coplanar

Can anyone please tell me if the correct answer is coplanar, line?

Answer 1

Coplanar, line
Since parallel lines are coplanar lines that do not intersect.

Answer 2

Ok thank you, that is what I thought.

Answer 3

yw :)

Answer 4

We were wrong it wasn't coplanar, line. But thanks for helping anyway.

Answer 5

Oh sorry, well you could have double checked yourself :)
Sorry though.

Answer 6

I was pretty sure I was right 0.0

Answer 7

Yeah I was sure I was right too.

Answer 8

But you said "We were wrong it wasn't coplanar, line." ?

Answer 9

Yes we were wrong but it is ok, I appreciate it anyway.

Answer 10

@jim_thompson5910 do you have a thought on this?

Answer 11

I have no clue what the correct answer is since it wasn't coplanar, line. do you?

Answer 12

@Directrix

Answer 13

The three undefined terms of Euclidean Geometry are point, line, and plane.

So, what is the definition of parallel lines. See which of those 3 terms are used.

Answer 14

Coplanar lines that do not intersect. --> parallel lines

I see "line" as the undefined term.

Answer 15

@marylou004 Look in your text and see how "parallel lines" are defined.

Answer 16

so Directrix so you also think it would be Coplanar, line?

Answer 17

If no more information is forthcoming, I would go with this option: Line, plane

Answer 18

The determining factor is how parallel lines are defined in @marylou004 's text.

Answer 19

@some_someone >>so Directrix so you also think it would be Coplanar, line?
No because "coplanar" is not an undefined term of classical Euclidean Geometry.

Answer 20

Oh okaii, hmm I see. Well I agree and depends how it is defined in her book, or by her instructor.