Trigonometric identities

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Geometric definitions and trigonometric identities

Geometry High-school concept

One angle is first a point on the unit circle, then sides of a triangle, then the sum of two angles.

Works

Work

Trigonometric identities and angle sums

Geometry High-school concept

Drag α and β on the unit circle and read the sum-to-product identities through the midpoint angle m and the offset d.

Exam visualizations

Exam

A 120° isosceles construction and the cosine law

112 AST Mathematics I, Fill-in 9 Isosceles trianglesAngle-sum formulas

112 AST Mathematics I, Fill-in 9: read the vertex angle and the base angles, then use an angle-sum formula and the cosine law for the squared distance between the new vertices.

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