Triangle Solver

Free online triangle solver. All triangle parameters (sides, angles, area). Accurate and easy to use.

Triangle Inputs

Side a

Side b

Side c

Angle A (°)

Angle B (°)

Angle C (°)

Solution (SSS)

Sides

a = 5.0000

b = 6.0000

c = 7.0000

Angles

A = 44.42°

B = 57.12°

C = 78.46°

Area: 14.6969

Perimeter: 18.0000

Semi-perimeter: 9.0000

Type: Scalene & Acute

Steps

Using Law of Cosines: cos(A) = (b² + c² − a²) / (2bc)

cos(A) = (6² + 7² − 5²) / (2 × 6 × 7)

cos(A) = (36 + 49 − 25) / 84

cos(A) = 0.7142857142857143

A = 44.42°

Same for B, then C = 180 − A − B