Tag Archives: Kagan High School Geometry

#made4math Monday! More Kagan, Triangle Center Foldable, Einthoven’s Triangle


A couple of weeks ago, I shared how much I was enjoying some of Kagan’s strategies!  We’ve been working with triangle congruence this past week.  I am a fan of the sequencing they’ve placed within these lessons.  From recognizing missing information, to stating congruencies, justifying each part.  This is an informal way to introduce the proofs, but each activity leads one step closer.

Today, our activities involved more of the Boss/Secretary and Pairs Check formats.  Tomorrow we are doing Blind Sequencing.  The idea is similar to ones I’ve seen others post – I think @misscalcul8 did some proofs on popsicle sticks back in the summer and I loved that idea!

Color Coded Cards for Proofs

I printed the 4 sets of each “proof” on color-coded card stock…notice, I highlighted/circled problem # in corresponding color.  This way students can come up and exchange a set once they  complete it.


Students are “forced” to talk about the math – the questions, discussions, (arguments) I’m hearing is wonderful!  They really like Boss/Secretary and even said they have to think about their choice of words – especially when the Secretary (Assistant) writes something completely different than what the Boss had intended.  The praise and coaching aspect is still a bit awkward for a few of them.  The questions they ask one another are so purposeful – they really want to know.  A great opportunity to observe learning / struggles.

Upon completion of the activty, I pop the answers on the overhead – allowing them to double check, a time for discussion, questions, clarifications.  Very interesting to hear students share different approaches to the same problem…and they want to know if its okay… 🙂

Triangle Centers Foldable

As we finished our triangle centers, students asked if I would make them “one of those cool charts” (aka foldable) to help organize all the names/sketches/special characteristics.  Its mostly blank, my first attempt at actually creating a foldable.  I printed it off, made copies and I had my sides reversed, but life goes on and my kiddos were okay with it.  Triangle Centers Foldable I only copied the front side and let them write the names on the inside of the flaps, so they can have “flashcard” style study tool.

Around the Clock

To fill in the center columns – I let them decide what was important.  I used the “Around the Clock” – is that Kagan or another book?  Sorry.  Students have a slip of paper, draw a circle and write in 12, 3, 6 and 9.  I give them 1 minute to go set up appointments with their classmates.  For example, if I made an appointment with Kelly at 3 – she would have my name on her card at 3 and I would have her name on my card.  I had a few stragglers, but it was a quick fix – asking who had an appointment at 6 open.  When they arrived at their appointment, I would write a specific topic, like median/centroid on the board and they were restricted to those topics at that appointment.  I gave them between 2 & 3 minutes to share discuss.  Time.  Move to your ___ appointment.

They loved it, I think.  And once again, they were TALKING about the math!

Cardiology Technician – application of Triangle Centers

While I was searching for some clipart for the foldable, I ran across a text problem from www.nexuslearning.com, about Einthoven’s Triangle for a person’s heart.  I tweaked it a bit, inserted a bigger graph, gave the students a piece of patty paper (how we’ve done the constructions they’ve needed) and assigned it for homework.  In Kentucky, we have program reviews of our accountability model – we must document/show student work samples that we are integrating Practical Living / Career Studies; Arts/Humanities and Writing/Communication…this will definitely be one of my samples for PLCS.

Cardiology Technician – assignment sheet

I left school today feeling successful for the first time this school year.  I know I’ll be back to treading water soon, so I’ll enjoy this small bit of time – smiling, because I loved what I was doing today!