Problem Solving with Right Triangles and Trig
Lesson 7 of 11
Objective: Students will be able to communicate their reasoning clearly and precisely by presenting their work to the class.
Warm-Up: Trig Tool Tag
Since my students have just learned about the sine and cosine ratios, I want to give them a structure that ensures equal participation as they practice solving. Trig Tool Tag requires students to write in their own color, taking turns solving each step of the problem in order to show high quality work. I ask a student volunteer to help me model what the process looks like, along with how we tag each other so that whoever is “it” is the person writing out his or her step of the work. Throughout this warm-up, I encourage students to do a mental check to make sure their answer is reasonable.
Because pairs will finish at different times, I must make sure there is something for early finishers to do. I extend students’ thinking by asking them to sort their triangles’ perimeters from least to greatest. A positive outcome of asking students to do this work is that they see there are several tools they can bring into the problem to help them solve, including the Pythagorean Theorem.
Students work on a quick individual “quiz” to get a sense of their facility with solving trigonometry problems. This quiz does not count for a grade but, instead, gives students a chance to assess their own understanding and to ask questions about points of confusion particularly because multiple choice problems often include great wrong answers that might have tricked them.
For this homework review activity, I assign one problem from the assignment to each group to present to the class. I give groups about 8 minutes to come to consensus about the answer to their problem and to write up one final draft of the problem. Ultimately, the Recorder/Reporter or another elected member of the group will project and explain the group’s work using the document camera.
I go over my expectations for students, telling them Recorder/Reporters will have approximately three minutes to do the following: read the problem out loud for the class, explain how their clearly labeled diagram represents the problem, and explain why their answer makes sense and how they know their answer is reasonable (MP6). Additionally, the Recorder/Reporter should be prepared to take answers from the class during this time.