11 20 28 triangle

Obtuse scalene triangle.

Sides: a = 11   b = 20   c = 28

Area: T = 88.18769463129
Perimeter: p = 59
Semiperimeter: s = 29.5

Angle ∠ A = α = 18.35879993921° = 18°21'29″ = 0.32204075335 rad
Angle ∠ B = β = 34.93547022415° = 34°56'5″ = 0.61097255773 rad
Angle ∠ C = γ = 126.7077298366° = 126°42'26″ = 2.21114595428 rad

Height: ha = 16.03439902387
Height: hb = 8.81986946313
Height: hc = 6.29990675938

Median: ma = 23.7011265789
Median: mb = 18.77549833555
Median: mc = 8.03111892021

Vertex coordinates: A[28; 0] B[0; 0] C[9.01878571429; 6.29990675938]
Centroid: CG[12.33992857143; 2.10996891979]
Coordinates of the circumscribed circle: U[14; -10.43880527786]
Coordinates of the inscribed circle: I[9.5; 2.98993880106]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.6422000608° = 161°38'31″ = 0.32204075335 rad
∠ B' = β' = 145.0655297758° = 145°3'55″ = 0.61097255773 rad
∠ C' = γ' = 53.29327016337° = 53°17'34″ = 2.21114595428 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    