My Favorite: Converse of the Pythagorean Theorem

Friday, January 22, 2016
Today was a GREAT teaching day (on a Friday)! As students walked in the classroom, this "Who Wants to be a Millionaire" question was posted on the board.

I told students to take out a piece of scratch paper and write down their answer. Students were engaged the moment they walked in the classroom. After about 3 minutes, I collected all of the answers and played the video. Students were so surprised that this was an actual question/video on "Who Wants to be a Millionaire?" I definitely wish there were more Geometry questions like this out there. If anybody has any, please share :)

After the video, we went over the Converse of the Pythagorean Theorem through this foldable/sorting activity. I completed 2-4 problems with the whole class (depending on their level) and I showed them how to get through each step to determine the type of triangle the given lengths will make.

After we completed the examples as a class, students finished the rest of the cards by themselves. Students were engaged and by the end of the lesson, they understand the Converse of the Pythagorean Theorem. When students asked for help, I sort of "sing-songed" the steps to help them remember it. Some loved and some hated this, but I think it stuck with them :). Once they were finished, they raised their hand, and I gave them this homework assignment.

Overall, I am VERY pleased with this activity, because over the past two years, my students seemed to struggle with this topic. I felt like this day went by EXTREMELY fast, so I will definitely be using this lesson again in the future. Here are all of the files that I used in my lesson: CLICK HERE


  1. What a great start having the millionaire clip. Thanks for sharing, sounds like a great lesson. Nikki :)

  2. That's great! I think I've seen it before, but I forget: did the guy on Millionaire get the question right?

    It's also great of you to share the resources, thanks for doing that! I can't tell from the resources if students are mainly doing this algebraically or if there's some looking at triangles & their side lengths involved. If not, that may be one more avenue to explore to cement their understanding: give the students a ruler and have the students draw a triangle of side lengths 3,4,6 and see what kind of triangle it is, so they get a picture of what's happening in their mind, geometrically. Just a thought!

    PS--There's a "Mr. Newell" teacher at my school and students are constantly getting him and me (Mr. Newman) mixed up!

    Thanks for sharing!

  3. He went with the audience/AOL and the audience happened to choose "A" so he got it wrong. I will definitely have students draw it out next year because few students are having a hard time using the theorem. Thanks for the idea :)

  4. This activity seems really great. I tried to get the files but the link does not seem to work. Any suggestions?

    1. Sorry, I just now saw your comment and I fixed it! :)

  5. I tried the Click Here and can't see your docs. Help!!! This looks so great!

  6. do u think u can sent me the answer key to this worksheet so i can go over it with my class

  7. the worksheet is called converse of the pythagorean theorem hw