# Triangle calculator SSS - result

Please enter the triangle sides:

### Obtuse scalene triangle.

Sides: a = 5   b = 11   c = 13

Area: T = 26.89221456935
Perimeter: p = 29
Semiperimeter: s = 14.5

Angle ∠ A = α = 22.09331769923° = 22°5'35″ = 0.38655986807 rad
Angle ∠ B = β = 55.83877404834° = 55°50'16″ = 0.97545524183 rad
Angle ∠ C = γ = 102.0699082524° = 102°4'9″ = 1.78114415545 rad

Height: ha = 10.75768582774
Height: hb = 4.88994810352
Height: hc = 4.13772531836

Median: ma = 11.77992189894
Median: mb = 8.17700673192
Median: mc = 5.54552682532

Inradius: r = 1.85546307375
Circumradius: R = 6.6476922192

Vertex coordinates: A[13; 0] B[0; 0] C[2.80876923077; 4.13772531836]
Centroid: CG[5.26992307692; 1.37990843945]
Coordinates of the circumscribed circle: U[6.5; -1.39898110038]
Coordinates of the inscribed circle: I[3.5; 1.85546307375]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 157.9076823008° = 157°54'25″ = 0.38655986807 rad
∠ B' = β' = 124.1622259517° = 124°9'44″ = 0.97545524183 rad
∠ C' = γ' = 77.93109174756° = 77°55'51″ = 1.78114415545 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    