# Triangle calculator SSS - result

Please enter the triangle sides:

### Acute scalene triangle.

Sides: a = 16   b = 17   c = 21

Area: T = 133.4921572768
Perimeter: p = 54
Semiperimeter: s = 27

Angle ∠ A = α = 48.40546480534° = 48°24'17″ = 0.84548204818 rad
Angle ∠ B = β = 52.61768015821° = 52°37' = 0.91883364295 rad
Angle ∠ C = γ = 78.97985503645° = 78°58'43″ = 1.37884357423 rad

Height: ha = 16.6866446596
Height: hb = 15.70548909138
Height: hc = 12.71334831207

Median: ma = 17.34993515729
Median: mb = 16.62107701386
Median: mc = 12.73877392029

Inradius: r = 4.94441323247
Circumradius: R = 10.69773044844

Vertex coordinates: A[21; 0] B[0; 0] C[9.71442857143; 12.71334831207]
Centroid: CG[10.23880952381; 4.23878277069]
Coordinates of the circumscribed circle: U[10.5; 2.04550729161]
Coordinates of the inscribed circle: I[10; 4.94441323247]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 131.5955351947° = 131°35'43″ = 0.84548204818 rad
∠ B' = β' = 127.3833198418° = 127°23' = 0.91883364295 rad
∠ C' = γ' = 101.0211449636° = 101°1'17″ = 1.37884357423 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    