Here is a step-by-step guide to using this lesson plan in the classroom/laboratory. We have suggested these steps as a possible plan of action. You may customize the lesson plan according to your preferences and requirements.

1.Topic introduction and discussion

Reading(25 -30min)

Use the resource, ‘Trigonometric ratios in right triangles’ by Khan Academy, to introduce the simple trigonometric ratios and their relation to right angled triangles.

First introduce the basic trigonometric functions like sine, cosine and tangent, and how they relate to the study of triangles and circles.

Then, discuss the trigonometric ratios in right triangles and how to use them to solve for unknown sides and angles. Use the embedded video to discuss several examples to enable your students to understand these concepts better.

Read More

2.Discuss further

Visualization(10 min)

Use the interactive tool, ‘Sea Level’ by NASA, to visualize the satellite observations of global sea level rise over time.

Explain that global warming is causing the rise in sea levels due to the melting of ice-sheets.

Emphasize that the sea levels are rising globally by an average of about 3mm/year.

Read More

3.Classroom/ Laboratory Activity

Visualization(10 min)

1. Use the figure provided above in this lesson plan, ‘Sea level rise and additional inland intrusion’ by Chirag Dhara in First post, to explain how sea level rise results in large-scale inundation of the coastline.
2. Use this depiction to explain to your students how trigonometric functions can be used to calculate the extent of land intrusion by the rising sea levels.
3. The gently sloping area adjoining the coast is called the Continental Shelf, where the average downward slope is only about 0.1^o as shown in the graphic above. Recall the NASA estimate of sea level rise to be about 3cm in 10 years as noted from the previous tool. Now ask your students to calculate the coastline retreat because of sea level rise. Use the tangent trigonometric function to calculate coastline retreat.
4. Discuss how the coastline retreat is disproportionately large for what would seem like a very small vertical rise in sea level.
5. What could be the implications of rising sea levels on the coastal regions globally?
6. How much has the coastline approximately receded since the 1850s to the present times?
7. How much do we expect it to recede by 2100?
8. Answer key: Sea levels have risen over 20 cm since 1850. Sea level is expected to rise further by 30 – 120cm by 2100 (Video; NASA’s Earth Minute: Sea Level Rise).

4. Questions/Assignments

• Learn the definition of trigonometric functions.
• Use trigonometric functions to relate the lengths of the sides of a right-angled triangle.
• Apply trigonometry to understand why even a small sea level rise due to global warming can affect coastlines.

Use this lesson plan to help your students find answers to:

1. What are derivatives and their functions?
2. Using an example, describe polynomial differentiation.
3. Is the extent of the Arctic Sea Ice decreasing since 1980?
4. Has the speed of melting of Arctic Sea Ice changed from 1980- 2017?
5. Discuss the Ice Albedo Feedback and Global Warming to explain the differences in rates of melting of and extent of Arctic Sea Ice over the past four decades.