Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 8.48552813742   b = 3.16222776602   c = 5.83109518948

Area: T = 6
Perimeter: p = 17.47985109293
Semiperimeter: s = 8.73992554646

Angle ∠ A = α = 139.3998705355° = 139°23'55″ = 2.43329663815 rad
Angle ∠ B = β = 14.03662434679° = 14°2'10″ = 0.24549786631 rad
Angle ∠ C = γ = 26.56550511771° = 26°33'54″ = 0.4643647609 rad

Height: ha = 1.41442135624
Height: hb = 3.79547331922
Height: hc = 2.05879830217

Median: ma = 2
Median: mb = 7.10663352018
Median: mc = 5.70108771255

Inradius: r = 0.68765573417
Circumradius: R = 6.51992024052

Vertex coordinates: A[0; 0] B[-3; 5] C[3; -1]
Centroid: CG[0; 1.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[2.74662293667; 0.68765573417]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 40.6011294645° = 40°36'5″ = 2.43329663815 rad
∠ B' = β' = 165.9643756532° = 165°57'50″ = 0.24549786631 rad
∠ C' = γ' = 153.4354948823° = 153°26'6″ = 0.4643647609 rad

How did we calculate this triangle?

1. We compute side a from coordinates using the Pythagorean theorem 2. We compute side b from coordinates using the Pythagorean theorem 3. We compute side c from coordinates using the Pythagorean theorem 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. 4. The triangle circumference is the sum of the lengths of its three sides 5. Semiperimeter of the triangle 6. The triangle area using Heron's formula 7. Calculate the heights of the triangle from its area. 8. Calculation of the inner angles of the triangle using a Law of Cosines     