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Triangle Calculator

Please provide 3 values including at least one side to the following 6 fields, and click the "Calculate" button. When radians are selected as the angle unit, it can take values such as pi/2, pi/4, etc.

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°
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Triangle Information

Triangle Types

Triangles can be classified based on their sides and angles:

  • Equilateral: All sides equal
  • Isosceles: Two sides equal
  • Scalene: No sides equal
  • Right: One angle is 90°
  • Obtuse: One angle > 90°
  • Acute: All angles < 90°

Important Formulas

Pythagorean Theorem: a² + b² = c²

Law of Sines: a/sin(A) = b/sin(B) = c/sin(C)

Area: (1/2) * base * height

Heron's Formula: √(s(s-a)(s-b)(s-c)), where s = (a+b+c)/2

Other Concepts

Median: Line from a vertex to the midpoint of the opposite side

Inradius: Radius of the inscribed circle

Circumradius: Radius of the circumscribed circle