6 12 15 triangle

Obtuse scalene triangle.

Sides: a = 6   b = 12   c = 15

Area: T = 34.19770393455
Perimeter: p = 33
Semiperimeter: s = 16.5

Angle ∠ A = α = 22.33216450092° = 22°19'54″ = 0.39897607328 rad
Angle ∠ B = β = 49.45883981265° = 49°27'30″ = 0.86332118901 rad
Angle ∠ C = γ = 108.2109956864° = 108°12'36″ = 1.88986200307 rad

Height: ha = 11.39990131152
Height: hb = 5.76995065576
Height: hc = 4.56596052461

Median: ma = 13.24876412995
Median: mb = 9.72111110476
Median: mc = 5.80994750193

Vertex coordinates: A[15; 0] B[0; 0] C[3.9; 4.56596052461]
Centroid: CG[6.3; 1.52198684154]
Coordinates of the circumscribed circle: U[7.5; -2.46773188561]
Coordinates of the inscribed circle: I[4.5; 2.07325478391]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 157.6688354991° = 157°40'6″ = 0.39897607328 rad
∠ B' = β' = 130.5421601874° = 130°32'30″ = 0.86332118901 rad
∠ C' = γ' = 71.79900431357° = 71°47'24″ = 1.88986200307 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    