## Wednesday, September 27, 2017

### Intro to Auxiliary Lines Warm Up & Activity

As we wrap up our first geometry unit this week, one thing we begin to discuss are auxiliary lines. My students already have so much background knowledge on parallel lines cut by a transversal from their middle school days (and our first few days of the year), so I wanted a short task to get them connecting what they've done before with where we are headed next.

Auxiliary Lines Warm Up

I designed this task as a way to get students thinking independently about how auxiliary lines might help us. The above diagram was given to them, along with a bunch of questions about angle pairs and measures. I had them work on this individually after they finished a quiz, then find a high five partner around the room with whom they could discuss their answers. For many this was a "duh" kind of activity. It transitioned well into more complicated diagrams, giving us a foundation to which we could refer.

Here's the actual Word file:

Two Truths and a Lie
I was inspired by this one from Math=Love Two Truths and a Lie Activity Template post, in which she had students create their own version of Two Truths and a Lie on a particular topic. This brief activity had students decide which statement was a lie and then explain why. They worked in partners and we debriefed as a class. In my more talkative classes it sparked a lot of debate. In my less talkative it involved a LOT of creeping on students' papers and calling on the right kids to share their answers (which some did not appreciate, especially on a 90 degree day during first block). Overall, though, I liked it and would the format again for other topics!

Again, the Word file:

Nothing groundbreaking but if anyone can use it, please steal!