Parallel Lines Homework ~stuck~

[darkmoon_jade]

Umm... I'm not sure I'm doing this right... check it if you would? (tis my first time here ^.^ ~feels kind of odd~ Please forgive me if I'm confusing.)

Here's the problem I'm on:
Find m<1 and then m<2. State the theorems or postulates that justify your answers.

My answers were:
<1=110* <2=120* Therom 7-1 and 7-2

are theroms different according to different books? My teachers never explained.

 

[pka]

If line AB is parallel to line DC then m∠ADC=100°
and m∠DC=70°

 

[Mrspi]

Re: Parallel Lines and Related Angles

Here's the problem I'm on:
Find m<1 and then m<2. State the theorems or postulates that justify your answers.

My answers were:
<1=110* <2=120* Therom 7-1 and 7-2

are theroms different according to different books? My teachers never explained.

Most geometry books contain the same theorems and postulates, but they may not appear in the same chapters in different books. So, "theorem 7-1" doesn't mean anything to me, even though I've taught geometry for years.

The two theorems that you need to apply to this problem are the ones which state (and wording may vary slightly in different texts):

If two parallel lines are cut by a transversal, then each pair of interior angles on the same side of the transversal are supplementary.

If two parallel lines are cut by a transversal, then each pair of alternate interior angles are equal (or congruent).

Your angle 1 and the angle with given measure 80 degrees are interior angles on the same side of the transversal. Your angle 2 and the angle with given measure 70 degrees are alternate interior angles. Apply the theorems to find the missing angle measures.

I never allowed my students to refer to theorems or postulates by number; it is much wiser to use a verbal statement of the postulate or theorem because that way, anyone familiar with geometry should be able to understand what you are saying.

 

[darkmoon_jade]

Oh, wow....thanks. I guess that kind of makes sence.

Umm, I need some help with this next problem... I hope you all don't mind...

(I don't know why I can't figure them out, but they don't make sence to me)

Lines L and m are parallel, and line t is a transversal. Under the rranslation <-4, -4>, the image of each of the angles <1, <2, <3, and <4, is it's ? angle.

Under rotation of 180* in point X, the image of each of the meaning of the prefix relates to the word transversal.

I've thought about it and thought about it, but everytime i look at it, the whole problem never makes sence to me...

 

[darkmoon_jade]

Wait...... is the answer to the first part is it's a right triangle?

 

[Mrspi]

Oh, wow....thanks. I guess that kind of makes sence.

Umm, I need some help with this next problem... I hope you all don't mind...

(I don't know why I can't figure them out, but they don't make sence to me)

Lines L and m are parallel, and line t is a transversal. Under the rranslation <-4, -4>, the image of each of the angles <1, <2, <3, and <4, is it's ? angle.

Under rotation of 180* in point X, the image of each of the meaning of the prefix relates to the word transversal.

I've thought about it and thought about it, but everytime i look at it, the whole problem never makes sence to me...

The translation <-4, -4> moves each point in the diagram four units to the left and 4 units down. In particular, let's focus on the point where line L and transversal t intersect (this is the common vertex for angles 1, 2, 3, and 4, and let's call it P). Do you see that moving this point four units left and four units down will make it coincide with the point where line M and transversal t currently intersect? Let's call this point Q. Q is the common vertex of angles 5, 6, 7 and 8. Angle 1 will coincide with angle 5, angle 2 will coincide with angle 6, and so forth. What do you call angle pairs like angle 1 and angle 5, or angle 2 and angle 6? Aren't they corresponding angles?

A translation "slides" each pre-image point to the left or right, and up or down.....
If you slide point P four units left and four units down, its image is Q. Do you see that you could also get from P to Q by moving along the transversal t? The distance you'd have to move along t can be found by using the Pythagorean Theorem.

I'm not exactly sure what your question is getting at, but perhaps this might help.

As to your second question, it seems to be incomplete. Did you copy the question correctly? If that is the complete question, I don't have any idea what they want.