Acute Triangle Calculator: Calculate Angles, Sides & Verify Triangle Type

Calculate Acute Triangle Angles and Verify Type

Discover the properties of an acute triangle with our easy-to-use Acute Triangle Calculator. Input your side lengths to instantly calculate angles and confirm if your triangle is acute, where all angles are less than 90 degrees.

Formula:

An acute triangle is a triangle where all three internal angles are less than 90 degrees. Our calculator uses the Law of Cosines to determine the angles from the given side lengths. The Law of Cosines for finding an angle (e.g., angle A) given sides a, b, c is:

  • Angle A: cos A = (b² + c² - a²) / (2bc)
  • Angle B: cos B = (a² + c² - b²) / (2ac)
  • Angle C: cos C = (a² + b² - c²) / (2ab)

Once all angles are calculated, the calculator checks if each angle is strictly less than 90° to classify the triangle as acute.

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