This lesson investigates and use the converse of alternate interior angles theorem, the converse of alternate exterior angles theorem, the converse of corresponding angles postulate, the converse of same side interior angles theorem and the converse of same side exterior angles theorem.

The first problem in the video covers determining which pair of lines would be parallel with the given information. You are given that two same-side exterior angles are supplementary. There two pairs of lines that appear to parallel. You must determine which pair is parallel with the given information. One could argue that both pairs are parallel, because it could be used, but the problem is ONLY asking for what can be proved with the given information.

Much like the lesson on Properties of Parallel Lines the second problem models how to find the value of x that allow two lines to be parallel. You much write an equation
based on how the angles are related. The problem in the video show how to solve a problem that involves converse of alternate interior angles theorem, converse of alternate exterior angles theorem, converse of corresponding angles postulate. Which means an equal relationship. Remember, the supplementary relationship, where the sum of the given angles is 180 degrees.

Similar to the first problem, the third problem has you determining which lines are parallel, but the diagram is of a wooden frame with a diagonal brace. Two alternate interior angles are marked congruent. Remember, you are only asked for which sides are parallel by the given information.

If you have a specific question, please ask. Cite your book, I might have it and I can show the specific problem. Also, give your best description of the problem that you can. You must quote the question from your book, which means you have to give the name and author with copyright date. I have used digital images of problems I have worked out by hand for the Algebra 2 portion of my blog.

[…] a paragraph proof on my math blog. I came back to this section, because the a previous post on Parallel Lines is my top page receiving hits, so I wanted to do something more. 3.2 Proving Lines Parallel […]

3.2 Proving The Converse of the Alternate Interior Angles Theorem «, on November 19, 2009 at 3:37 am said:[…] a paragraph proof on my math blog. I came back to this section, because the a previous post on Parallel Lines is my top page receiving hits, so I wanted to do something more. 3.2 Proving Lines Parallel […]

Mr. Pi, on November 19, 2009 at 3:44 am said:This has been my most popular page over the last couple of weeks and I have been paying attention to the search terms that my readers are using to access my blog. So, I wrote a paragraph proof and created a flow proof of the Converse of the Alternate Interior Angles Theorem.

Micheal, on April 28, 2012 at 5:50 am said:Just saying that it’s a helpful video but the music in the background is not very helpful and pretty off putting