Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 10.77703296143   b = 8.24662112512   c = 2.82884271247

Area: T = 6
Perimeter: p = 21.84549679903
Semiperimeter: s = 10.92224839951

Angle ∠ A = α = 149.0366243468° = 149°2'10″ = 2.60111731533 rad
Angle ∠ B = β = 23.19985905136° = 23°11'55″ = 0.40548917863 rad
Angle ∠ C = γ = 7.76551660184° = 7°45'55″ = 0.1365527714 rad

Height: ha = 1.11441720291
Height: hb = 1.45552137502
Height: hc = 4.24326406871

Median: ma = 3
Median: mb = 6.70882039325
Median: mc = 9.48768329805

Inradius: r = 0.54993255932
Circumradius: R = 10.46768789787

Vertex coordinates: A[2; 4] B[4; 6] C[0; -4]
Centroid: CG[2; 2]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[1.28217597175; 0.54993255932]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 30.96437565321° = 30°57'50″ = 2.60111731533 rad
∠ B' = β' = 156.8011409486° = 156°48'5″ = 0.40548917863 rad
∠ C' = γ' = 172.2354833982° = 172°14'5″ = 0.1365527714 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     