math
posted by nicole 4th grade .
I dontunderstand this question can you please help me. "Explain why 3 separate lines can all be parallel to each other,but 3 separate lines cannot all be perpendicular to each other. Use a drawing to show your answer."

three separate lines can be perpendicular, if you are considering three dimensional space, like on your table. One pencil laying on the table, a second pencil on the table perpendicular to the first, and a third pencil pointing straight up (not laying on the table, as you are holding it upwards.
So if you consider three lines in the same plane, as laying on your table, two of them can be perpendicular, but it is impossible to put a third pencil on the table perpendicular to both of the first two. 
These are parallel lines:

These are two perpendicular lines:
+
Do you see why we can only have one pair of perpendicular lines? 
Thank You very much

You're very welcome.