General Triangle

From sides a, b, c (SSS) computes perimeter, area (Heron), and angles via the cosine law.

Perimeter

12,00

Area

6,00

Angle A

36,87°

Angle B

53,13°

Angle C

90,00°

Area via Heron’s formula; angles from the law of cosines.

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Formula

SSS: P = a+b+c; A = √[s(s−a)(s−b)(s−c)] (Heron); angles via cosine law

Example: a = 3, b = 4, c = 5 → P = 12, A = 6, C = 90°

Methodology

Area S = (1/2) × base × height or Heron's formula from three sides. Perimeter = sum of sides.

Example

Sides 3, 4, 5: perimeter 12, area 6 (right triangle).

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