Special Right Triangles

learning_notes

Last updated: 8/16/2025

Key Concepts:

  • Two common types of special right triangles:
    • (30°-60°-90°) Triangle: The sides are in the ratio: (1:\sqrt{3}:2)
    • (45°-45°-90°) Triangle: The sides are in the ratio: (1:1:\sqrt{2})
  • The height of an equilateral triangle splits it into two congruent (30°-60°-90°) triangles.

Skills Covered:

  • Using side ratios to find missing lengths in special triangles.
  • Applying special triangle ratios to equilateral triangles and isosceles right triangles to calculate missing side lengths or area.

Example Problems:

  • Find the hypotenuse in a (45°-45°-90°) triangle where each leg is 7 cm.
  • Calculate the area of an equilateral triangle whose side length is 6.

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