Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 10.19880390272   b = 5.65768542495   c = 6.32545553203

Area: T = 16
Perimeter: p = 22.1799448597
Semiperimeter: s = 11.09897242985

Angle ∠ A = α = 116.5655051177° = 116°33'54″ = 2.03444439358 rad
Angle ∠ B = β = 29.74548812969° = 29°44'42″ = 0.51991461142 rad
Angle ∠ C = γ = 33.6990067526° = 33°41'24″ = 0.58880026035 rad

Height: ha = 3.13878581622
Height: hb = 5.65768542495
Height: hc = 5.06596442563

Median: ma = 3.16222776602
Median: mb = 8
Median: mc = 7.61657731059

Inradius: r = 1.44327770763
Circumradius: R = 5.70108771255

Vertex coordinates: A[-5; 4] B[1; 2] C[-9; 0]
Centroid: CG[-4.33333333333; 2]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[2.52548598835; 1.44327770763]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 63.43549488229° = 63°26'6″ = 2.03444439358 rad
∠ B' = β' = 150.2555118703° = 150°15'18″ = 0.51991461142 rad
∠ C' = γ' = 146.3109932474° = 146°18'36″ = 0.58880026035 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     