# 19 22 28 triangle

### Acute scalene triangle.

Sides: a = 19   b = 22   c = 28

Area: T = 208.4432887861
Perimeter: p = 69
Semiperimeter: s = 34.5

Angle ∠ A = α = 42.59111780237° = 42°35'28″ = 0.74333562888 rad
Angle ∠ B = β = 51.59332135275° = 51°35'36″ = 0.99004714477 rad
Angle ∠ C = γ = 85.81656084488° = 85°48'56″ = 1.4987764917 rad

Height: ha = 21.9411356617
Height: hb = 18.94993534419
Height: hc = 14.88987777044

Median: ma = 23.31884476327
Median: mb = 21.24985293609
Median: mc = 15.05499169433

Inradius: r = 6.04218228366
Circumradius: R = 14.03774182589

Vertex coordinates: A[28; 0] B[0; 0] C[11.80435714286; 14.88987777044]
Centroid: CG[13.26878571429; 4.96329259015]
Coordinates of the circumscribed circle: U[14; 1.02442613801]
Coordinates of the inscribed circle: I[12.5; 6.04218228366]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 137.4098821976° = 137°24'32″ = 0.74333562888 rad
∠ B' = β' = 128.4076786473° = 128°24'24″ = 0.99004714477 rad
∠ C' = γ' = 94.18443915512° = 94°11'4″ = 1.4987764917 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    