# Triangle calculator SSS - result

Please enter the triangle sides:

### Acute scalene triangle.

Sides: a = 9   b = 11   c = 12

Area: T = 47.32986382648
Perimeter: p = 32
Semiperimeter: s = 16

Angle ∠ A = α = 45.81656148467° = 45°48'56″ = 0.87996333279 rad
Angle ∠ B = β = 61.21877953194° = 61°13'4″ = 1.06884520891 rad
Angle ∠ C = γ = 72.96765898339° = 72°58' = 1.27435072366 rad

Height: ha = 10.517747517
Height: hb = 8.60552069572
Height: hc = 7.88881063775

Median: ma = 10.59548100502
Median: mb = 9.06991785736
Median: mc = 8.06222577483

Inradius: r = 2.95880398915
Circumradius: R = 6.27552703414

Vertex coordinates: A[12; 0] B[0; 0] C[4.33333333333; 7.88881063775]
Centroid: CG[5.44444444444; 2.62993687925]
Coordinates of the circumscribed circle: U[6; 1.8388210504]
Coordinates of the inscribed circle: I[5; 2.95880398915]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 134.1844385153° = 134°11'4″ = 0.87996333279 rad
∠ B' = β' = 118.7822204681° = 118°46'56″ = 1.06884520891 rad
∠ C' = γ' = 107.0333410166° = 107°2' = 1.27435072366 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    