Using Trigonometric Ratios

Louise Wolfe
Learning Focused Lesson Plan – iMovie Project

Essential Question: How can you use the trigonometric ratios (Sine, Cosine, and Tangent) to measure the real life height of immeasurable objects?

Concept: What is the Law of Sines?
Concept: What is the Law of Cosines
Concept: How can we use the Law of Sines and Law of Cosines to calculate immeasurable objects.

Lesson Essential Question: Based on the angle-side relationships, when and why do we use the Law of Sines?
Lesson Essential Question: Based on the angle-side relationships, when and why do we use the Law of Cosines?
Lesson Essential Question: How do we decide which law is better to use?

Launch Activity:
Using the concepts previously learned, the students will go out and find objects that they normally wouldn’t be able to measure.

Students will need to know:
• Law of Sines
• Law of Cosines
• Right Triangle Trigonometry
• How to use the Law of Sines
• How to use the Law of Cosines
• How to use these Laws to evaluate for real-world applications and models.
• The students will be responsible for making a clinometer.
• The students will also be responsible for deciding on which Laws to use in order to solve the problem
• They will use the information that they have gathered and put it all together as an iMovie project to show the class how they managed to measure the heights of immeasurable objects.

Student Assessments:
• Students have already taken a test on the Law of Sines and Law of Cosines
• Students will now be expected to complete an iMovie project as specified.

Assessment 1:
• Students will work on their iMovie project in school with their group. Their movie will then be presented to the class for further discussion and evaluation.


Students will construct a clinometer, complete all calculations, and film (using flip cameras)their group measuring the heights using the clinometer and mathemetical concepts, convert their work into an iMovie, and present the movie to their classmates. In groups of 3, students will come together and solve the problem of how to calculate the height of an object that would otherwise be immeasurable. Furthermore, they will discuss what calculations may work best for individual scenarios. Students will edit and revise all of their calculations and video clips and be sure that it’s easy to understand for a casual observer and that anyone could recreate their findings