Acute and Obtuse Triangles
I.SectionObjectives
- Identify and use the Law of Sines.
- Identify and use the Law of Cosines.
II.ProblemSolvingActivity-TeachingTime
- For this activity, the students will be divided into groups of 4−6. Then in this larger group, divide the group
into smaller sections of 2−3 people. - Each team will be assigned one of the Laws.
- Each team has the assignment of teaching the other team about their Law.
- First, the team must design a problem that they think best illustrates the Law of Sines or the Law of Cosines.
- Then they must prepare their presentation.
- Finally, the teams present their work to the other teams.
- Each team needs to evaluate the other.
- You can use a rubric for evaluations.
- Some possible points might be:
- Clarity of explanation
- Is the work accurate?
- Did you learn something new about the law?
- Allow time for students to share about their experience when finished.
III.MeetingObjectives
- Students will identify and use the Law of Sines.
- Students will identify and use the Law of Cosines.
- Students will demonstrate understanding through their presentation.
IV.NotesonAssessment
- Observe each group as it presents.
- You won’t get to see all of it, but do your best to get an idea of how each group is doing. Make notes on the
presentations. - Collect all notes from each group.
- Then compare student evaluations with your evaluations.
- Assign each group a final grade.
5.8. Right Triangle Trigonometry