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<\/p>\nFirst day of term 4 (which was Monday – I really am running behind at the moment!) saw the start of our Trigonometry unit with Year 9. I wanted a way to get my students to start thinking about how the angles of a right-angled triangle affect its sides, while also defining the Opposite and Adjacent sides. They already all remembered the Hypotenuse from doing Pythagoras’ Theorem \ud83d\ude42<\/p>\n
So I took the class out to the front lawn and had groups of students form right-angled triangles by standing at the corners. (Actually, I didn’t say “stand at the corners” the first time, which was a good reminder that I sometimes need to be clearer with my instructions. One group tried to form the sides of the triangle by lying on the ground.) In each group, one student was given a pink sticky note to indicate they were the right angle, and another had a green sticky note with θ written on it.<\/p>\n
Then using different colours of party streamers, the students made the sides of the triangles, defining the Opposite and Adjacent sides as we went.<\/p>\n
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As they did this, I had the groups check the other groups around them to make sure they all had right-angled triangles. This provoked great conversations amongst the groups, as they evaluated each other’s work and had to communicate clearly their reasons why a triangle was or was not right-angled.<\/p>\n
Then I gave this challenge: make the angle at θ bigger.<\/p>\n
As they did this, the students needed to work and talk with each other to figure out what they were going to do. Students communicating about maths to figure out a problem together! It also worked well that different groups used different solutions – some shortened the adjacent length, others lengthened the opposite – allowing us to discuss those different solutions.<\/p>\n
Once back inside, we then worked on defining the trigonometric ratios, eventually creating this notebook page:<\/p>\n
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There was more to the lesson than that, but I’m getting sleepy now \ud83d\ude42 I might elaborate on what other work we did next time.<\/p>\n
One more thing: as we were outside, a friend of mine happened to be driving past the school. As I was talking to him that night, he asked me two questions:<\/p>\n
I’m a little concerned about how convincing our triangles were now…<\/p>\n","protected":false},"excerpt":{"rendered":"
First day of term 4 (which was Monday – I really am running behind at the moment!) saw the start of our Trigonometry unit with Year 9. I wanted a way to get my students to start thinking about how the angles of a right-angled triangle affect its sides, while also defining the Opposite and … <\/p>\n