Math Is Fun Forum

jenny.marie.grace1

Guest

Geometry

Hi, I am just starting out in my geometry class and am quite confused. When I turned in my lesson I was surprised with the amount I had actually gotten correct. I answered 15 questions successfully but I missed 5 questions. I missed the following;

8. Imagine you printed out figure 1, 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?

AThe measure of ls_BC would be greater; the measure of ln_DF would not change; the measure of ry_EG would not change.
BThe measure of ls_BC,  ln_DF, and  ry_EG would not change.
CThe measure of ln_DF and ry_EG would be greater, but the rest would stay the same.
DThe measure of ls_BC and  ln_DF would be greater, and the rest would stay the same.
E All of their measures would be greater.
F All of their measures would stay the same.

I answered with F

11. Does every ray contain a line segment?

AOnly if there are three points on the ray
BYes, because all you need for a line segment is one point
CNo, because an element can't be two things
DNo, 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

I answered with D

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
E Yes, because any two points can be used to make a line
F Only if you make GE a line as well

I answered with A

16. Do two rays always define a plane?

ANo, because a ray can't be used to define a plane
BYes, because we need three points
CNo, because two rays might only make one line
DYes, because rays can be extended into lines
E No, because there aren't enough points
F Yes, because it's the number of points that matter

I answered with B

17. If I have an angle between 10 and 170 degrees, do I have a plane?

AOnly if you have an additional point not on the angle
BYes, because a ray always defines 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

I answered with E

I'm not looking for you to give me the answer but I would like some help to steer me in the right path, thank you.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,179

Re: Geometry

Hi jenny.marie.grace1,

You are in the right path.

Please see the following links too:

Parallel Lines and Angles.

Line.

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.