Triangle calculator VC

Please enter the coordinates of the three vertices

Acute scalene triangle.

Sides: a = 13.89224439894   b = 11.18803398875   c = 12.16655250606

Area: T = 65
Perimeter: p = 37.23883089375
Semiperimeter: s = 18.61991544688

Angle ∠ A = α = 72.89772710309° = 72°53'50″ = 1.27222973952 rad
Angle ∠ B = β = 50.28112406284° = 50°16'52″ = 0.8787573201 rad
Angle ∠ C = γ = 56.82114883406° = 56°49'17″ = 0.99217220574 rad

Height: ha = 9.35876047597
Height: hb = 11.6287553483
Height: hc = 10.68659341748

Median: ma = 9.3944147114
Median: mb = 11.88004237212
Median: mc = 11.04553610172

Inradius: r = 3.49110285593
Circumradius: R = 7.26876025853

Vertex coordinates: A[-8; -2] B[4; -4] C[-3; 8]
Centroid: CG[-2.33333333333; 0.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[2.99002391108; 3.49110285593]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 107.1032728969° = 107°6'10″ = 1.27222973952 rad
∠ B' = β' = 129.7198759372° = 129°43'8″ = 0.8787573201 rad
∠ C' = γ' = 123.1798511659° = 123°10'43″ = 0.99217220574 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     