# POTW – Deceiving Parallel Problem

What this is: I am going to highlight problems I used with my honors geometry students that I thought were valuable. You can see all posts in this series here. I am taking no claim that these are necessarily original as I might have stolen them from many of you reading this!

How I used it: This was a problem I threw at my students during class while we were working on parallel lines.

What is it: This tests to see if students are reading carefully and pay attention to their angle pairs.

Why I like it: It caused a debate in all of my classes because half of the students said x = 7 and the other half said x = 8. It is great when you can have them argue with each other and then hold a discussion about it.

Let me know if you used this and how it went!

# POTW – Crook Problem

What this is: I am going to highlight problems I used with my honors geometry students that I thought were valuable. You can see all posts in this series here. I am taking no claim that these are necessarily original as I might have stolen them from many of you reading this!

How I used it: This was a problem I threw at my students during class while we were working on parallel lines.

What is it: This is a classic crook problem but initially stumped a lot of students immediately.

Why I like it: Anytime I can give a problem nobody knows how to solve right away is great. Many of them drew some crazy triangles and could eventually reason it out. I liked that I could draw in an auxiliary line and introduce that idea that since two points determine a line, I can draw one in parallel to the other two anywhere I want in the diagram. It was great because they immediately asked if I could make up another one for them to complete.

Let me know if you used this and how it went!

# Lazy Lines: I want them to be straight!

I am trying to identify things that annoy me this year so I can fix them.

Lots of things annoy me: the copy machine breaking down in my desperate need for five more copies, the kid who decides he should sharpen his pencil right as I am summarize the most important idea of the day, the wi-fi network being fickle, etc. I’ll spare you all of my troubles.

One thing that students do (or more like not do) is drawing lines. Anytime we have to graph a line I get really annoyed when they are jagged, look more like a curve, or bent in some odd shape that makes me ponder if students are just completely screwing with me.

Here is my fix: Give students a ruler. Not just for the classroom but ALL THE TIME. No more crummy homework either. No excuses. So, I went to amazon and bought a bunch of little rulers that are pretty inexpensive and plastic so they are less likely to break being shoved into a binder, pencil case, or the bottom of a backpack (anybody have one of those students?)

All 8 designs

The first time we need to graph something we pull these out. I let students pick whichever one they like. They get to keep them. I have pirates and animals so everyone can be happy right?

Now I do not have to be annoyed…..or at least not by line drawings anymore. Those other things I mentioned earlier still annoy me.

# POTW – First Parallel Proof

What this is: I am going to highlight problems I used with my honors geometry students that I thought were valuable. You can see all posts in this series here. I am taking no claim that these are necessarily original as I might have stolen them from many of you reading this!

How I used it: This was an opener problem I used the first day after I taught parallel lines.

What is it: This is a proof that practices using formal two column proof with parallels. It forces students to practice their reasons.

Why I like it: I like that students have to first practice the congruent complements theorem because even my honors students want to say substitution. Then, they have to prove the lines parallel using a converse to the original statements we learned the class before. Then, they end the proof using a straightforward statement. I think it is important that students have to practice and wrestle with knowing when to end their reasons with parallel or end it with an angle pair congruent.

Let me know if you used this and how it went!

# POTW – Polygon Intro

What this is: I am going to highlight problems I used with my honors geometry students that I thought were valuable. You can see all posts in this series here. I am taking no claim that these are necessarily original as I might have stolen them from many of you reading this!

How I used it: Before I taught students what a polygon was, I just showed them some examples and some non-examples.

What is it: I used this in a powerpoint and had students, on their own, create their own definition of what an example was. As I revealed one example and then a non-example, I could see students constantly erasing and changing their definitions. Then, I had them work together and challenge each other’s definitions. Then, we moved on to practicing their definition. Only after, I told them that these were called polygons.

Why I like it: Instead of me telling my students what they need to know, they figured it out on their own. It appeared that everyone had the correct way to define a polygon before class was over and I did not have to do anything but guide them in the right direction and allow for discussion. So much more engagement than just telling them what the definition is and telling students to apply it.

Here is a link to the powerpoint if you want to try it out. Let me know if you used this and how it went!

# POTW – Transversal Angle Challenge

What this is: I am going to highlight problems I used with my honors geometry students that I thought were valuable. You can see all posts in this series here.

How I used it: After students learned about the different types of angle pairs, they got to complete this challenge.

What is it: Students all went to the board with a partner and drew the diagram. With a marker and an eraser in hand, they had to try and put the numbered angles in the diagram so every statement was true.

Why I like it: So much discussion! Students were arguing (in the best way possible) over which angle goes where and why something was or was not a type. It was tricky because we had just learned the basics on a diagram with one transversal and now their were three! They learned that certain angles could be interior or exterior depending on what transversal they were looking at (or at least that is what they told me when we had a class discussion after the activity). I just acted as an answer key and when students asked me if it was right, I would just point out a counterexample and walk away. It was lots of fun and a nice way to get students up and engaging with the ideas.

Let me know if you used this and how it went!

# POTW: Beginning Proof – Angle Bisector

I have been slacking on this lately so here is hoping I can pick right up and keep going…

What this is: I am going to highlight problems I used with my honors geometry students that I thought were valuable. You can see all posts in this series here.

How I used it: This was a question we completed in class together as students were practicing proofs.

What is it: This involves students using the congruent complements theorem and angle bisector definition.

Why I like it: My students were tripped up about how to prove something is an angle bisector since they had to use the converse to the definition of an angle bisector (which I make my students write everything in if-then form at the moment). It was great discussion about how to use it and since it was our first problem that involved using a converse, now many are much more careful in checking.

Let me know if you used this and how it went!