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Topic: i need help!!!
Replies: 9   Last Post: Feb 25, 2009 8:50 PM

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Posts: 181
Registered: 12/4/04
Re: i need help!!!
Posted: May 30, 2006 4:38 PM
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> I am a highschool student taking a geometry class
> online and I just want to know

I would not ordinarily respond to a question that just seeks homework help, but these questions are so basic that I'm afraid the student really doesn't understand what's going on.
> 1.Two lines perpendicular to the same line are
> perpendicular to each other.
> A. true
> B. false

Absolutely true in TWO dimensions, absolutely false in THREE dimensions.
> 2. All coplanar lines are parallel.
> A. true
> B. false

Coplanar lines lie in one plane. Can't you have two lines lying in one plane which intersect? Like "V"
> 3. Any pair of perpendicular lines are coplanar.
> A. true
> B. false

Since any two intersecting lines determine a plane, true.
> 4. If two segments are parallel, the lines containing
> them are coplanar.
> A. true
> B. false

If the segments are parallel, the lines containing them are parallel (by definition), so they must be coplanar.
> 5. Segments which share a common endpoint must be
> perpendicular.
> A. true
> B. false

So clearly false. Draw any number of diagrams of 2 intersecting lines forming an obique (non-right) angle. Like the letter V .

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