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[quote=bob bundy]hi zee-f

Thanks for the link.  I thought it would need a password; after all, they are selling this set of courses.  But it was useful to look at the sample lessons.

Couldn't get to a sample on geometry so I looked up the definitions on Mathswords.com.  (I have never used the term 'ray' before in geometry)

[quote]#2- I choose (A)

2. Two points define a line, but if there are two lines in a plane, and if they intersect somewhere, they “define” a single point.  If there are two planes in space, and they intersect, what do they define?  (Look at the walls of your room, where they meet. Imagine if there were no floor or ceiling, and the walls went up and down and side to side forever, what would the corner where they meet look like?) 
A-a ray 
B-a line 
C-a point 
D-a plane 
E-a partridge 
F-a pear tree[/quote]
[color=red]As the question says the planes go on forever, I think this should be B- a line   [/color]

[quote]#4- I choose (D)

4. What is the difference between a plane and a piece of paper? 
A- Nothing, both can have lines and points on them 
B-You can draw on paper not on a plane 
C-You can make a piece of paper into a plane if you know how to fold it 
D-A plane is two dimensional and goes on infinitely, a piece of paper has three dimensions and has definite boundaries 
E- Nothing, because they are the same thing 
F- Planes are used in mathematics, paper is not[/quote]
[color=red] I like your answer.  :)  [/color]
[quote]#5- I choose (A)

5. I have ry_AY and ry_XZ.  Given only what you've been told, is it possible that they could define an angle?
 
A-No, because they do not have a common endpoint 
B-Yes, because it takes two rays to make an angle 
C-No, because there should be a line there 
D-Yes, because Y is close to Z in the alphabet 
E-No, because ry_AY is very long 
F-Yes, if they are on the same plane[/quote]
[color=red]  I like your answer :) [/color]
[quote]#11- I choose (D)

11. Does every ray contain a line segment?
A-Only if there are three points on the ray 
B-Yes, because all you need for a line segment is one point 
C-No, because an element can't be two things 
D-No, because the end point is really an arrow 
E-Yes, because every ray needs two points to define it 
F-No because the points are busy making a ray[/quote]
[color=red] If a line segment means a part of an infinite line defined by two end points, then I think this should be E.  [/color]
[quote]#12- I choose (D)

12. How many points are on a line? 
A- None 
B-Lots, because lines are infinite 
C-2 
D-We only need two points to define a line, but a line contains an infinite number of points 
E-5 or 6 depending on how long the line is 
F-At least 10[/quote]
[color=red] Answer D is good!  [/color]
[quote]13- I choose (E)

13. Does every line contain a ray? 
A- Yes, because a ray and a line both have arrows. 
B-No, because the two points necessary for a ray are making a line. 
C-Yes, because a ray needs two points to exist, which are always part of a line. 
D-Sometimes, if the arrows are in the right places 
E- No, because lines don't end and a ray needs an endpoint 
F- Only if the line has three points on it[/quote]
[color=red]  Choose a point on the line to be the end of the ray and then it would appear to be C [/color]
[quote]#16- I choose (E)

16. If I have two rays, do I have a plane?

A-No, because a ray can't be used to define a plane 
B-Yes, because we need three points 
C-No, because two rays might only make one line 
D-Yes, because rays can be extended into lines, and two would make a plane 
E-No, because there aren't enough points 
F-Yes, because it's the number of points that matter[/quote]
[color=red] If a point has a ray going from it in one direction, and another ray going from it in the opposite direction, then all you have is a line.  So answer C looks right to me.  [/color]
[quote]#17- I choose (C)

17. If I have an angle, do I have a plane? 
A-Only if you have an additional point not on the angle 
B-Yes, because any two rays can define a plane 
C-No, because there aren't enough points 
D-Yes, because angles are big 
E- No because rays cannot be extended into lines 
F-Yes, because that means you have two lines that meet at a single point[/quote]
[color=red] An angle is made from two rays from a single point.  Take a second point on one ray and a third point on the other ray and you have three points (not in a line) so you do have a plane.  [/color]
[quote]#20- I choose (E)

20. Does every ray eventually create an angle?

A- Only if the ray is also a line. 
B-Only if the ray has another point on it 
C-Yes, because every ray eventually crosses something 
D-No, because a ray can only be a ray 
E- No, because a ray only makes an angle at the endpoint 
F-No, because it may never cross another line[/quote]
[color=red] If you only have this ray then it, on its own, does not make a angle.  So maybe D, but I think I choose answer F[/color]

Bob[/quote]

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Topic review (newest first)

zee-f: 2012-09-02 03:56:22

Your welcome Bobbym...

Bob Bundy your welcome, and

Each course has many lessons around 20-30 and the lesson is explained then on the bottom there are questions to answer.
I feel like am student and a teacher at the same. No tests only questions and a grade for each lesson. When I finish all the lessons I submit a Credit Report Form (CRF) to get a grade for the whole course.

bobbym: 2012-09-02 03:10:07

Hi all;

Thanks for the answers.

bob bundy: 2012-09-02 02:10:23

hi zee-f,

Thanks for telling us the answers your teacher was expecting. I seem to remember, way back, that I thought 15 E was a posible answer.

How are you expecting to be assessed for this work ? Will you have to do an exam ?

Bob

zee-f: 2012-09-02 00:40:37

These are the correct answers
15-E
17-F

I got a 9 from 10

zee-f: 2012-09-01 23:35:56

17. If I have an angle, do I have a plane?

17. I choose (F)Yes, because that means you have two lines that meet at a single point.
Explanation:
I have a common point another point on ray 1 + another point on ray 2 now I have three points and rays can be used to create a line. To have a plane two lines have to intersect in a single point, and an angle intersects in a single point.So,
I have a plane.

zee-f: 2012-09-01 23:23:41

I posted this to my teacher:

15- I choose A-No, because rays need one endpoint

15- Explanation:
Well as mentioned in the lesson because a ray continues indefinitely in one direction, but has a definite endpoint in the other direction, but a line needs two points to define it but it goes beyond these points it doesn't have a starting or ending point it keeps going forever.

she said #15 is incorrect. If a ray exists, then it contains the two points that are needed to define and name it. How many points are needed to define and name a line?

am going to submit this as a new answer:

#15- Two points are needed to define and name a line. So the right answer is (E)

15. In figure 1 above, can ry_EH be used to create a line?

E- Yes, because any two points can be used to make a line

But for #17- B, and E were in correct answers.

bob bundy: 2012-09-01 17:47:46

Good morning zee-f and bobbym,

I think 16C too.

I'm going to have a long think about 17.

Back after that.

LATER EDIT:

From Mathswords.com: angle = Two rays sharing a common endpoint.

I have an angle
=> I have two rays sharing a common endpoint
=> I have a common point + another point on ray 1 + another point on ray 2
=> I have three points
=> I have a plane
=> Answer B is correct

Bob

bobbym: 2012-09-01 10:29:15

I originally had C in post #16. Let me know what they give as the right answer.

zee-f: 2012-09-01 10:28:11

I think am going to try E

17- E-No because rays cannot be extended into lines

17-Explanation:
To have a plane two lines have to intersect in a single point or are parallel. Rays have an end point they cant extend to lines. lines don't have end points to start or end them they just have two points to define them.

Ok enjoy am going to rest to

bobbym: 2012-09-01 10:18:22

An angle is two rays with a common endpoint. Try F then as long as the rays are two different ones with a common endpoint.

See you later, going to eat.

zee-f: 2012-09-01 10:14:48

or E because a ray has an end point and a line doesn't

zee-f: 2012-09-01 10:12:31

But in the lesson it mentioned that A plane is defined by any of the following:

three points not lying on a line
a line and a point not lying on the line
two lines which intersect in a single point or are parallel

So doesn't that make 17-F because an angle has unites two rays in a single end point so then we have two lines that meet at a single point and two lines which intersect in a single point or are parallel are defined as a plane

zee-f: 2012-09-01 10:02:43

Now am stuck on #17 B was incorrect when I submitted it to my teacher I still don't get why?

17. If I have an angle, do I have a plane?

A Only if you have an additional point not on the angle
BYes, because any two rays can define a plane
CNo, because there aren't enough points
DYes, because angles are big
E No because rays cannot be extended into lines
F Yes, because that means you have two lines that meet at a single point

zee-f: 2012-09-01 10:00:56

Well after reading the lesson two more times I came up with this

14- I choose D-Yes, because every line segment can be extended into a line

14- Explanation:
Yes ls_BC can become a line because Every line contains a line segment, and every line segment can be extended into a line.

15- I choose A-No, because rays need one endpoint

15- Explanation:
Well as mentioned in the lesson because a ray continues indefinitely in one direction, but has a definite endpoint in the other direction, but a line needs two points to define it but it goes beyond these points it doesn't have a starting or ending point it keeps going forever.

bobbym: 2012-09-01 09:48:21

Hi Bob;

Who are you hiding your answers from ?

In case she wants to work on it a little more without seeing mine. Also, in case someone else pops in and would like to answer the questions.

On some other forums they insist you hide your answer to any post. That allows other people to post their answers. I know we do not have that many people answering questions but...

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