# Triangle calculator SSS - result

Please enter the triangle sides:

### Obtuse scalene triangle.

Sides: a = 11   b = 20   c = 28

Area: T = 88.18769463129
Perimeter: p = 59
Semiperimeter: s = 29.5

Angle ∠ A = α = 18.35879993921° = 18°21'29″ = 0.32204075335 rad
Angle ∠ B = β = 34.93547022415° = 34°56'5″ = 0.61097255773 rad
Angle ∠ C = γ = 126.7077298366° = 126°42'26″ = 2.21114595428 rad

Height: ha = 16.03439902387
Height: hb = 8.81986946313
Height: hc = 6.29990675938

Median: ma = 23.7011265789
Median: mb = 18.77549833555
Median: mc = 8.03111892021

Inradius: r = 2.98993880106
Circumradius: R = 17.46329019871

Vertex coordinates: A[28; 0] B[0; 0] C[9.01878571429; 6.29990675938]
Centroid: CG[12.33992857143; 2.10996891979]
Coordinates of the circumscribed circle: U[14; -10.43880527786]
Coordinates of the inscribed circle: I[9.5; 2.98993880106]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.6422000608° = 161°38'31″ = 0.32204075335 rad
∠ B' = β' = 145.0655297758° = 145°3'55″ = 0.61097255773 rad
∠ C' = γ' = 53.29327016337° = 53°17'34″ = 2.21114595428 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    