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## Intro to SOHCAHTOA

Summary

The lesson provides a foundational understanding of trigonometry, focusing on the concept of similar triangles and the introduction of SOHCAHTOA for calculating the ratios of sides in right-angled triangles.

- Trigonometry is fundamentally based on the properties of similar triangles, where two triangles are considered similar if they share two equal angles, leading to proportional sides.
- SOHCAHTOA is a mnemonic that helps remember the three primary trigonometric ratios: sine (opposite over hypotenuse), cosine (adjacent over hypotenuse), and tangent (opposite over adjacent).
- These ratios remain constant for any given angle across all similar right-angled triangles, allowing for the calculation of unknown sides given one side and one acute angle.
- The lesson emphasizes the practical application of these concepts through examples and practice problems, demonstrating how to use trigonometric ratios and the Pythagorean theorem to solve for unknowns in triangles.
- It also introduces the Pythagorean Identity (cosine squared theta plus sine squared theta equals 1) as an important trigonometric formula.

Chapters

00:04

Introduction to Similar Triangles

02:11

Understanding SOHCAHTOA

03:36

Applying Trigonometry to Solve Problems

08:49

The Pythagorean Identity