Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 12.36993168769   b = 2.23660679775   c = 10.77703296143

Area: T = 9
Perimeter: p = 25.37657144686
Semiperimeter: s = 12.68878572343

Angle ∠ A = α = 131.6343539337° = 131°38'1″ = 2.29774386675 rad
Angle ∠ B = β = 7.76551660184° = 7°45'55″ = 0.1365527714 rad
Angle ∠ C = γ = 40.6011294645° = 40°36'5″ = 0.70986262721 rad

Height: ha = 1.45552137502
Height: hb = 8.0549844719
Height: hc = 1.67112580436

Median: ma = 4.7176990566
Median: mb = 11.54333963806
Median: mc = 7.07110678119

Inradius: r = 0.70993396335
Circumradius: R = 8.27547943915

Vertex coordinates: A[10; -3] B[6; 7] C[9; -5]
Centroid: CG[8.33333333333; -0.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[5.20218239787; 0.70993396335]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 48.36664606634° = 48°21'59″ = 2.29774386675 rad
∠ B' = β' = 172.2354833982° = 172°14'5″ = 0.1365527714 rad
∠ C' = γ' = 139.3998705355° = 139°23'55″ = 0.70986262721 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     