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mike mcgarry
lesson by mike mcgarry
magoosh expert

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 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 principal trigonometric ratios: sine (opposite/hypotenuse), cosine (adjacent/hypotenuse), and tangent (opposite/adjacent).
  • these ratios remain constant for any right triangle with a given acute angle, allowing for the calculation of unknown sides given one side and one acute angle.
  • the lesson emphasizes the practical application of these concepts through example problems, demonstrating how to use trigonometric ratios and the pythagorean theorem to solve for unknowns in right triangles.
  • understanding and applying the pythagorean identity (cosine squared theta plus sine squared theta equals 1) is also highlighted as a crucial part of trigonometry.
chapters
00:00
introduction to similar triangles
02:11
understanding sohcahtoa
03:36
applying trigonometric ratios
08:49
the pythagorean identity