# 7 16 19 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 16   c = 19

Area: T = 54.22217668469
Perimeter: p = 42
Semiperimeter: s = 21

Angle ∠ A = α = 20.8999027966° = 20°53'57″ = 0.36547568485 rad
Angle ∠ B = β = 54.62334598481° = 54°37'24″ = 0.95333592232 rad
Angle ∠ C = γ = 104.4787512186° = 104°28'39″ = 1.82334765819 rad

Height: ha = 15.49219333848
Height: hb = 6.77877208559
Height: hc = 5.70875544049

Median: ma = 17.21219144781
Median: mb = 11.8744342087
Median: mc = 7.8989866919

Inradius: r = 2.58219888975
Circumradius: R = 9.81215578104

Vertex coordinates: A[19; 0] B[0; 0] C[4.05326315789; 5.70875544049]
Centroid: CG[7.68442105263; 1.9032518135]
Coordinates of the circumscribed circle: U[9.5; -2.45328894526]
Coordinates of the inscribed circle: I[5; 2.58219888975]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 159.1010972034° = 159°6'3″ = 0.36547568485 rad
∠ B' = β' = 125.3776540152° = 125°22'36″ = 0.95333592232 rad
∠ C' = γ' = 75.52224878141° = 75°31'21″ = 1.82334765819 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    