Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 8.6022325267   b = 2.82884271247   c = 5.83109518948

Area: T = 2
Perimeter: p = 17.26217042866
Semiperimeter: s = 8.63108521433

Angle ∠ A = α = 165.9643756532° = 165°57'50″ = 2.89766139905 rad
Angle ∠ B = β = 4.57439212599° = 4°34'26″ = 0.08798299857 rad
Angle ∠ C = γ = 9.4622322208° = 9°27'44″ = 0.16551486774 rad

Height: ha = 0.4654990555
Height: hb = 1.41442135624
Height: hc = 0.68659943406

Median: ma = 1.58111388301
Median: mb = 7.21111025509
Median: mc = 5.70108771255

Inradius: r = 0.23217268291
Circumradius: R = 17.7344147851

Vertex coordinates: A[-4; 1] B[1; 4] C[-6; -1]
Centroid: CG[-3; 1.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[2.89765853643; 0.23217268291]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 14.03662434679° = 14°2'10″ = 2.89766139905 rad
∠ B' = β' = 175.426607874° = 175°25'34″ = 0.08798299857 rad
∠ C' = γ' = 170.5387677792° = 170°32'16″ = 0.16551486774 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     