Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 10.19880390272   b = 8.24662112512   c = 13.4166407865

Area: T = 42
Perimeter: p = 31.86106581434
Semiperimeter: s = 15.93303290717

Angle ∠ A = α = 49.3998705355° = 49°23'55″ = 0.86221700547 rad
Angle ∠ B = β = 37.87549836511° = 37°52'30″ = 0.66110431689 rad
Angle ∠ C = γ = 92.72663109939° = 92°43'35″ = 1.61883794301 rad

Height: ha = 8.23768776758
Height: hb = 10.18664962515
Height: hc = 6.2610990337

Median: ma = 9.89994949366
Median: mb = 11.18803398875
Median: mc = 6.40331242374

Inradius: r = 2.63664803772
Circumradius: R = 6.71658052992

Vertex coordinates: A[-2; -4] B[4; 8] C[6; -2]
Centroid: CG[2.66766666667; 0.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[3.3989760485; 2.63664803772]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 130.6011294645° = 130°36'5″ = 0.86221700547 rad
∠ B' = β' = 142.1255016349° = 142°7'30″ = 0.66110431689 rad
∠ C' = γ' = 87.27436890061° = 87°16'25″ = 1.61883794301 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     