Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 12.04215945788   b = 6.40331242374   c = 5.83109518948

Area: T = 6.5
Perimeter: p = 24.27656707111
Semiperimeter: s = 12.13878353555

Angle ∠ A = α = 159.6243564786° = 159°37'25″ = 2.78659567693 rad
Angle ∠ B = β = 10.67697828045° = 10°40'11″ = 0.18662228404 rad
Angle ∠ C = γ = 9.70766524093° = 9°42'24″ = 0.16994130439 rad

Height: ha = 1.08795912381
Height: hb = 2.03302589046
Height: hc = 2.22994816069

Median: ma = 1.11880339887
Median: mb = 8.90222469074
Median: mc = 9.19223881554

Inradius: r = 0.53655155849
Circumradius: R = 17.29218731125

Vertex coordinates: A[0; -5] B[-5; -8] C[4; 0]
Centroid: CG[-0.33333333333; -4.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[2.84223519507; 0.53655155849]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 20.37664352138° = 20°22'35″ = 2.78659567693 rad
∠ B' = β' = 169.3330217196° = 169°19'49″ = 0.18662228404 rad
∠ C' = γ' = 170.2933347591° = 170°17'36″ = 0.16994130439 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     