Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 6.40331242374   b = 11.18803398875   c = 6.32545553203

Area: T = 17
Perimeter: p = 23.90880194453
Semiperimeter: s = 11.95440097226

Angle ∠ A = α = 28.74397952917° = 28°44'23″ = 0.50216040542 rad
Angle ∠ B = β = 122.9055242923° = 122°54'19″ = 2.1455101157 rad
Angle ∠ C = γ = 28.35549617853° = 28°21'18″ = 0.49548874424 rad

Height: ha = 5.31099079042
Height: hb = 3.04110524494
Height: hc = 5.37658720223

Median: ma = 8.5
Median: mb = 3.04113812651
Median: mc = 8.54440037453

Inradius: r = 1.42221169628
Circumradius: R = 6.65883714251

Vertex coordinates: A[5; 0] B[-1; 2] C[-6; -2]
Centroid: CG[-0.66766666667; 0]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0.92201933289; 1.42221169628]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.2660204708° = 151°15'37″ = 0.50216040542 rad
∠ B' = β' = 57.0954757077° = 57°5'41″ = 2.1455101157 rad
∠ C' = γ' = 151.6455038215° = 151°38'42″ = 0.49548874424 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     