# 8 15 19 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 15   c = 19

Area: T = 57.2366352085
Perimeter: p = 42
Semiperimeter: s = 21

Angle ∠ A = α = 23.68219072912° = 23°40'55″ = 0.41333272554 rad
Angle ∠ B = β = 48.86604895851° = 48°51'38″ = 0.85327764174 rad
Angle ∠ C = γ = 107.4587603124° = 107°27'27″ = 1.87554889808 rad

Height: ha = 14.30990880213
Height: hb = 7.63215136113
Height: hc = 6.02548791668

Median: ma = 16.64333169771
Median: mb = 12.5
Median: mc = 7.36554599313

Inradius: r = 2.72655405755
Circumradius: R = 9.95987059489

Vertex coordinates: A[19; 0] B[0; 0] C[5.26331578947; 6.02548791668]
Centroid: CG[8.08877192982; 2.00882930556]
Coordinates of the circumscribed circle: U[9.5; -2.98876117847]
Coordinates of the inscribed circle: I[6; 2.72655405755]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 156.3188092709° = 156°19'5″ = 0.41333272554 rad
∠ B' = β' = 131.1439510415° = 131°8'22″ = 0.85327764174 rad
∠ C' = γ' = 72.54223968763° = 72°32'33″ = 1.87554889808 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    