# Triangle calculator SSS - result

Please enter the triangle sides:

### Acute scalene triangle.

Sides: a = 128   b = 90   c = 130

Area: T = 5439.00657915
Perimeter: p = 348
Semiperimeter: s = 174

Angle ∠ A = α = 68.39550345954° = 68°23'42″ = 1.19437185457 rad
Angle ∠ B = β = 40.82331687687° = 40°49'23″ = 0.71224987061 rad
Angle ∠ C = γ = 70.78217966359° = 70°46'54″ = 1.23553754018 rad

Height: ha = 84.98444654922
Height: hb = 120.8676795367
Height: hc = 83.6777012177

Median: ma = 91.67333330909
Median: mb = 120.9010785771
Median: mc = 89.53877015564

Inradius: r = 31.25986539742
Circumradius: R = 68.83661098245

Vertex coordinates: A[130; 0] B[0; 0] C[96.86215384615; 83.6777012177]
Centroid: CG[75.62105128205; 27.89223373923]
Coordinates of the circumscribed circle: U[65; 22.65985528172]
Coordinates of the inscribed circle: I[84; 31.25986539742]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 111.6054965405° = 111°36'18″ = 1.19437185457 rad
∠ B' = β' = 139.1776831231° = 139°10'37″ = 0.71224987061 rad
∠ C' = γ' = 109.2188203364° = 109°13'6″ = 1.23553754018 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    