Triangle calculator SSS - result

Please enter the triangle sides:

Acute scalene triangle.

Sides: a = 21   b = 27   c = 28

Area: T = 266.5710816107
Perimeter: p = 76
Semiperimeter: s = 38

Angle ∠ A = α = 44.84768191535° = 44°50'49″ = 0.78327246533 rad
Angle ∠ B = β = 65.05436961589° = 65°3'13″ = 1.13554011886 rad
Angle ∠ C = γ = 70.09994846876° = 70°5'58″ = 1.22334668118 rad

Height: ha = 25.38876967721
Height: hb = 19.74659863783
Height: hc = 19.04107725791

Median: ma = 25.42114476378
Median: mb = 20.74224685127
Median: mc = 19.72330829233

Inradius: r = 7.01550214765
Circumradius: R = 14.88991017327

Vertex coordinates: A[28; 0] B[0; 0] C[8.85771428571; 19.04107725791]
Centroid: CG[12.28657142857; 6.3476924193]
Coordinates of the circumscribed circle: U[14; 5.06880716656]
Coordinates of the inscribed circle: I[11; 7.01550214765]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 135.1533180846° = 135°9'11″ = 0.78327246533 rad
∠ B' = β' = 114.9466303841° = 114°56'47″ = 1.13554011886 rad
∠ C' = γ' = 109.9010515312° = 109°54'2″ = 1.22334668118 rad

How did we calculate this triangle?

1. The triangle circumference is the sum of the lengths of its three sides 2. Semiperimeter of the triangle 3. The triangle area using Heron's formula 4. Calculate the heights of the triangle from its area. 5. Calculation of the inner angles of the triangle using a Law of Cosines     