Sine, Cosine, and Tangent

Right-triangle methods for sine, cosine, and tangent.

Lesson 3 of 53 parts Practice Flashcards

1/3

Sine Ratio

Objective: Apply sine ratio.

sin θ = opposite/hypotenuse.

Worked examples

Try itFor acute θ, opposite=3 and hypotenuse=5. Find sin θ.Show answer

3/5. Sine = opposite/hypotenuse = 3/5.

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Objective: Apply sine ratio.

sin θ = opposite/hypotenuse.

Worked examples

Try itFor acute θ, opposite=3 and hypotenuse=5. Find sin θ.Show answer

3/5. Sine = opposite/hypotenuse = 3/5.

Objective: Apply cosine ratio.

cos θ = adjacent/hypotenuse.

Worked examples

Try itFor acute θ, adjacent=4 and hypotenuse=5. Find cos θ.Show answer

4/5. Cosine = adjacent/hypotenuse = 4/5.

Objective: Apply tangent ratio.

tan θ = opposite/adjacent, when adjacent is nonzero.

Worked examples

Try itFor acute θ, opposite=3 and adjacent=4. Find tan θ.Show answer

3/4. Tangent = opposite/adjacent = 3/4.

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