16 17 21 triangle

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

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?

Now we know the lengths of all three sides of the triangle and the triangle is uniquely determined. Next we calculate another its characteristics - same procedure as calculation of the triangle from the known three sides SSS. 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    