
 zeef
 Super Member
Re: Naming Geometry Elements
Ok sounds good
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 bob bundy
 Moderator
Re: Naming Geometry Elements
#1 C
1. We need two points to define a line. A different way to say this is that if you have two points, you will need at least a line to hold them. In this sense, what do you need at least three points to define?
A three lines Ba ray Can angle or a plane Da line or an angle E a line segment F a point
C is a good answer!
3.E 3. In the figure below(IMG), compare the two rays ry_AB and ry_CD. Which one is longer?
A ry_CD Bry_AB Cry_CD because the arrow goes right Dry_CD because the points are further apart E all rays are the same infinite length Fry_AB we just can't see it all
I like your answer
#6 F
6. Consider two lines that intersect in a single point in a plane. How many rays would it take to draw the same picture? A3 B5 C1 D2 E6 F4
F is correct, well done!
#9 A
9. Plane geometry as we study it now can be traced back to Euclid, and his book The Elements. Go HERE (http://www.greenlion.com/EuI17.pdf ) to find out more about that book, and find out what it means when they say "A point is that which has no part." Which of these best sums up that idea:
AA point has no dimensions, it only defines a place in space BPoints are only on lines, never by themselves CA point is only important if it defines a shape DPoints are very big EPoints are very small FPoints stand alone and have nothing more to them
I also think answer A!
#10 C
10. Imagine you printed out figure 1 and enlarged it with a photocopier, then compared the two figures. Everything would appear larger. Would point B really be larger?
AYes, it would become a planet BNo, because the line it is on would not be bigger CYes, because everything would be bigger DNo, because a point has no dimensions to enlarge EYes, because point B is on a line segment FNo, because I think the answer choice should be F
The photocopier makes it bigger, but we must think of the point a dimensionless. So it would not really (in our Euclidean World) be larger.
#18 D
18. If I have a line, do I have a plane?
A. Only if you have an additional point not on the line B.Only if it is a long line C.Yes, because lines are big D.Yes, because a line has an infinite number of points E.Only if the line has three points on it F Only if the line has 6 or more points on it
Not D. To make a plane you need a point that is not on the line as well. That is answer ???
19A
19.If I have three points, do I always have a plane?
AYes, because three points are enough BYes, because planes are infinite COnly if the points are on the same line DNo, because all the points may be on the same line ENo, you might have an angle F No, you might have a triangle
Take care here. Three points only make a plane if they are not all in a line. So you should say answer ???
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
 zeef
 Super Member
Re: Naming Geometry Elements
Thank you so much for the clues they helped a lot here are my new answers for:
10 D
18 A
19 D
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 bobbym
 Administrator
Re: Naming Geometry Elements
In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof.
 zeef
 Super Member
Re: Naming Geometry Elements
Thanks guys .
These are the last 4 questions in this lesson they all talk about the same image below
7 B
7. Look at the picture below Imagine that at the intersection of ry_EG and ln_DF we placed a point M. Which of the following most completely describes the new elements have we created?
A <GMF and ls_EM
B <GMF, ry_MD and ls_EM
C four rays
D one angle
E ry_MD and ry_MF
F ry_MG
8 F
8. Imagine you printed out the picture below, enlarged it with a photocopier, and then compared the two figures. Everything would look larger, but many of these things would not actually be larger because they are really infinite. Knowing this, tell me how would ls_BC change? How would ln_DF change? How would ry_EG change? How would <GEH change?
Als_BC would be bigger, ln_DF would not be bigger, ry_EG would not be bigger, <GEH would not be bigger
BAll of them would be larger
CThey would get fuzzier looking
D ls_BC would be bigger, ln_DF would be bigger, and the rest would stay the same
E ln_DF would be bigger, and ry_EG would be bigger, but th rest would stay the same
F Nothing would change
14F 14. In figure 1 above, could ls_BC become a line?
A Maybe if there's nothing in the way BYes, if we can find another point CNo, because there aren't enough points DYes, because every line segment can be extended into a line E No, because it can't cross ry_EH F No because it doesn't have arrows
15.A 15. In figure 1 above, can ry_EH be used to create a line?
ANo, because rays need one endpoint BNo, because <GEH can't have a line in it CYes, but only if it doesn't make <GEH anymore DNo, because there aren't enough points EYes, because any two points can be used to make a line FOnly if you make GE a line as well
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 bob bundy
 Moderator
Re: Naming Geometry Elements
7 B
7. Look at the picture below Imagine that at the intersection of ry_EG and ln_DF we placed a point M. Which of the following most completely describes the new elements have we created?
A <GMF and ls_EM
B <GMF, ry_MD and ls_EM
C four rays
D one angle
E ry_MD and ry_MF
F ry_MG
B seems best out of the choices ... but I'd like to add some more facts!
8 F
8. Imagine you printed out the picture below, enlarged it with a photocopier, and then compared the two figures. Everything would look larger, but many of these things would not actually be larger because they are really infinite. Knowing this, tell me how would ls_BC change? How would ln_DF change? How would ry_EG change? How would <GEH change?
Als_BC would be bigger, ln_DF would not be bigger, ry_EG would not be bigger, <GEH would not be bigger
BAll of them would be larger
CThey would get fuzzier looking
D ls_BC would be bigger, ln_DF would be bigger, and the rest would stay the same E ln_DF would be bigger, and ry_EG would be bigger, but th rest would stay the same
F Nothing would change
Line segments get bigger.
14F 14. In figure 1 above, could ls_BC become a line?
A Maybe if there's nothing in the way BYes, if we can find another point CNo, because there aren't enough points DYes, because every line segment can be extended into a line E No, because it can't cross ry_EH F No because it doesn't have arrows
Not sure as the wording is vague. I would say D, as I'm assuming that "extend into a line" means adding the extra bits of line with arrows.
15.A 15. In figure 1 above, can ry_EH be used to create a line?
ANo, because rays need one endpoint BNo, because <GEH can't have a line in it CYes, but only if it doesn't make <GEH anymore DNo, because there aren't enough points EYes, because any two points can be used to make a line FOnly if you make GE a line as well
I think of a ray as "half a line". So I would extend the ray the other way to make it into a full line. This would be answer ???
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
 bob bundy
 Moderator
Re: Naming Geometry Elements
hi bobbym,
Who are you hiding your answers from ?
zeef: 10, 18 and 19 are now correct!
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
 zeef
 Super Member
Re: Naming Geometry Elements
#8 B 14 confused because a line segment needs two points and it cant be larger then these point but a line goes on and on and they uses arrows to say they go on
15 am thinking F
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 zeef
 Super Member
Re: Naming Geometry Elements
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 zeef
 Super Member
Re: Naming Geometry Elements
Hey Bob Bundy,
what were facts you wanted to add?
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 zeef
 Super Member
Re: Naming Geometry Elements
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 bob bundy
 Moderator
Re: Naming Geometry Elements
I think A is correct!
14 confused because a line segment needs two points and it cant be larger then these point but a line goes on and on and they uses arrows to say they go on
I think the correct answer is D
F ??? Why do you think you must make another line too?
E looks like the correct answer to me. A ray has a starting point and at least one more point to define the direction of the ray.
So use these points to specify the line.
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
 zeef
 Super Member
Re: Naming Geometry Elements
am still really confused on 14, 15, 17
17 B is incorrect I posted that
But for 14, 15 am still stuck I don't get it this lesson can get confusing
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 zeef
 Super Member
Re: Naming Geometry Elements
A line goes on and on but the ray has a end point
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 zeef
 Super Member
Re: Naming Geometry Elements
so 15 A ? because a ray is in a single direction from an endpoint but a line doesn't have a starting or ending point it keeps going for ever all it need is two points to define it.
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 bob bundy
 Moderator
Re: Naming Geometry Elements
It is after midnight here in the UK so I'm going to have to stop after this post and look again in the morning.
I think 17B is correct. I can only think that I am getting tied up in the wrong definition for a ray, a line and a plane. The problem is I have done geometry for many years and never needed to use the term ray, so it is confusing me too.
Have you been given definitions for these terms? If so, post them please.
Now for Q7.
I have made the diagram below with M marked.
I think that adds the following:
ray MG ray MF ray MD line segment EM line segment MG angle GMF angle GMD angle DME angle EMF
Bye for now, see you tomorrow.
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
 zeef
 Super Member
Re: Naming Geometry Elements
Good night and thank you for alll the help
The definitions they gave me are these
Line Segment:The set of all points that lie between two selected points. Or, the shortest distance between two points.
Line: The entire set of points that lie in a location in one direction or in the opposite direction, at any distance, from a particular point. Every line contains a line segment, and every line segment can be extended into a line.
Ray A ray is the set of points lying in a single direction from an endpoint. In an intuitive way, a ray is ½ of a line, because it continues indefinitely in one direction, but has a definite endpoint in the other direction. To define a ray, you need one endpoint, and then a second point somewhere along the ray (not the same as the endpoint) to define the direction
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 bobbym
 Administrator
Re: Naming Geometry Elements
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...
In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof.
 zeef
 Super Member
Re: Naming Geometry Elements
Well after reading the lesson two more times I came up with this
14 I choose DYes, 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 ANo, 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.
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 zeef
 Super Member
Re: Naming Geometry Elements
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
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 zeef
 Super Member
Re: Naming Geometry Elements
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 17F 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
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 zeef
 Super Member
Re: Naming Geometry Elements
or E because a ray has an end point and a line doesn't
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 bobbym
 Administrator
Re: Naming Geometry Elements
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.
In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof.
 zeef
 Super Member
Re: Naming Geometry Elements
I think am going to try E
17 ENo because rays cannot be extended into lines
17Explanation: 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
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
 bobbym
 Administrator
Re: Naming Geometry Elements
I originally had C in post #16. Let me know what they give as the right answer.
In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof.
