geometry help? Parallelism?

Question

Okay so I can not begin to understand even the lesson itself, and I am not prepared to christmas tree the test. So here it is:

is AB || CD:

1. If angle 4 = 60° and angle 5 = 60°?
A maybe
B 15
C yes
D no
E it possibly might be
F none of the above

Look I need a explaination of what she's asking(in lameins terms). The point is she ONLY provided me with examples of word problems and now I am confused at what she's asking.It would also be great is any of you knew of a website that relates to this. Thank you, community.

I gave you this example to show exactly what I am talking about, I just need a perfect explaination so I can comprehend the lesson.

You can use your own examples for paralism, I really don't mind. Please go into detail and break every little step down-it would help bunches.

Answer 1

You don't tell us what angle 4 and angle 5 are, so let's do this:
Draw two || lines (AB and CD) and then draw a third line (the transversal) that crosses each of the two || lines.

You will find that eight angles are formed, four by the transversal intersecting the top || line AB, and four more by the transversal intersecting the bottom || line CD.

Label the top 4 angles 1,2,3 and 4 starting int upper left and proceding clockwise. Do the same with the bottom 4 angles, labling them 5,6,7, and 8.

Now if you have done everything right, the angles on the left of the transversl from top to bottom should be 1,4,5,and 8. The angles onthe right side of the transversal from top to bottom should be 2,3,6,7.

AB || CD if:
angle1 = angle 7
angle 2= angle 8
angle 1 = angle 5
angle 4 = angle 8
angle 2 = angle 6
angle 3 = angle 7
angle 3 = angle 5
angle 4 = angle 6
angle 4 + angle 5 = 180 degrees
angle 3 + angle 6 = 180 degrees

Now if your teacher has numbered the angles the same way that I have, then the answer is none of the above.

The 60 degrees is unimportant. What's important is if the proper pair of angles are equal. It could be 40 degrees or 70 degrees or whatever.

Answer 2

you don't show what angles correspond to angle 4 or 5, but there's a simple way to find the answer:

AB means line AB, ie, a line that PASSES THROUGH point A and B. the same with line CD.
when two lines are parallel, it means that they will never intersect each other, even if each line was infinitely long. Mathematically what this means is that lines AB and CD have the same slope. Do you know how to calculate the slope of each line? each point has an X and a Y number, ie

A = (Ax,Ay) where

Ax = x-coordinate
Ay = Y coordinate

to calculate the slope, compute:

slope = rise/run = (By-Ay)/(Bx-Ax)

slope(of line CD) = (Dy-Cy)/(Dx-Cx)

if these two numbers are the same, the lines are parallel

Answer 3

Do you have a figure to look at so that we can see where angles 4 & 5 are? That makes a difference.

Answer 4

Without the diagram, it's impossible to tell. Here are some sites that give basic geometry help. Hopefully they can help you out.

http://www.mathleague.com/help/geometry/basicterms.htm

http://www.freemathhelp.com/geometry.html

Answer 5

We can't help you without a diagram.

Answer 6

The word is "layman's" terms.