Week 14: Trigonometry

During week 14 we looked at different trigonometry topics in the math curriculum. In grade 10, students learn the primary trigonometric ratios. I remember being in grade 10 and being taught trig ratios by memorizing SOH CAH TOA.  The activity we looked at took a much different approach to introducing students to the concept.

The activity introduced the primary trigonometric ratios using a hands-on inquiry method. The first trig ratio being introduced was tangent, but this same activity could be used with sine or cosine. Students began the activity by measuring and recording the length of the sides of triangles that were drawn on the classroom floor using tape. These triangles were drawn so that there were 3 sets of similar triangles. Students would then calculate the ratio of the opposite and adjacent sides and talk about what they noticed and wondered about the results. Students would see that the similar triangles had the same ratio results and questions could then be asked about finding values for triangles other than the 3 similar triangles.

I really like the idea of this activity because I feel like students would gain a better understanding of what they are doing and connect it to their previous unit on similar triangles.  I think it is easy to introduce a topic like primary trig ratios by simply providing the formula for ratios and not provide students with the opportunity to understand what it is these ratios mean. This is an activity I would really like to try with a future grade 10 class.

Another strategy this activity reminded me of was taking time in lessons to ask students what they notice and wonder. By asking these questions students are able to really think about the problem being presented, connect their thinking, and ask questions. I hope to be able to use the I notice and I wonder prompt during my next teaching block.