Electrical mathQuestion 488 of 1506

A right triangle has an adjacent side of 4 and a hypotenuse of 5. Which function relates these two sides to the designate angle?

  1. Sine
  2. Tangent
  3. Pythagorean theorem
  4. Cosine
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Correct answer: Cosine

Cosine is adjacent over hypotenuse: 4/5 = 0.8.

Source: Trigonometry and Single Phase AC Generation for Electricians (Flinn), 1.5: Trigonometry Functions

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Questions last reviewed: 18 October 2026