Trigonometry is due to be revisited by foundation tier year 11 this week and next. Judging by the attempts at a question involving right angled trig on their most recent mock exams they definitely needed this. It was clear from the responses on the mock that what students could remember varied from absolutely nothing to writing out SohCahToa and not getting any much further.
I know there's a debate about whether memory tools like SohCahToa are the right way to go about approaching trigonometry but with these guys having missed 6 months and it clearly being something they'd been shown in the past I wasn't about to get into the pros and cons of it. Rather I decided my time would be better spent ensuring that they had a better understanding of how the labeling of their triangles was connected to the appropriate ratio by this tool.
This was where my idea came from to work both forwards and backwards on key processes involved in solving a problem involving right angled trig.
First we began with the classic - label your triangles.
We then looked at the reverse. Could the students identify the appropriate angle, given the way I had labeled the triangle?
After this we practiced working on choosing the correct ratio of the 3 based on information given. Once students were happy with this we had a look at creating an equation based on the information given.
This in itself was fine and showed me that the students were able to form an equation based on the information given but to check that they really understood where the equations came from we then looked at the reverse. How would they do when given an equation and an empty right angled triangle?
I was pleasantly surprised that with minimal teaching students were able to adapt what they knew about forming equations to these problems.
I'm not saying this is the correct way to teach right angled trigonometry but today, with this particular class it was what they needed to build on fragments of what they could remember.
Find the resources from this article available for download here:
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