Advanced 12 min read
3D Geometry: Extending Right Triangle Math to Three Dimensions
3D geometry from right triangles: 3D distance is √(Δx² + Δy² + Δz²) and a box diagonal is √(l² + w² + h²), plus direction angles and vectors.
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Advanced 10 min read
Inverse Trig Functions: Arcsin, Arccos & Arctan Explained
Inverse trig functions (arcsin, arccos, arctan, or sin⁻¹, cos⁻¹, tan⁻¹) turn a side ratio back into an angle. Ranges, worked examples and common mistakes.
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Advanced 11 min read
Law of Cosines: Solve Any Triangle (Not Just Right Triangles)
The Law of Cosines, c² = a² + b² - 2ab·cos(C), solves non-right triangles from SAS or SSS. Worked examples for sides and angles, plus navigation problems.
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