Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 7.28801098893   b = 15.29770585408   c = 8.06222577483

Area: T = 4.5
Perimeter: p = 30.63994261784
Semiperimeter: s = 15.32197130892

Angle ∠ A = α = 4.18549161251° = 4°11'6″ = 0.07330405653 rad
Angle ∠ B = β = 171.1879620448° = 171°10'47″ = 2.98876479891 rad
Angle ∠ C = γ = 4.63554634269° = 4°38'8″ = 0.08109040992 rad

Height: ha = 1.23662450755
Height: hb = 0.58883484054
Height: hc = 1.11663126113

Median: ma = 11.67326175299
Median: mb = 0.70771067812
Median: mc = 11.28105141727

Inradius: r = 0.29437391826
Circumradius: R = 49.8880412544

Vertex coordinates: A[0; -9] B[1; -1] C[3; 6]
Centroid: CG[1.33333333333; -1.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-1.89329858432; 0.29437391826]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 175.8155083875° = 175°48'54″ = 0.07330405653 rad
∠ B' = β' = 8.8220379552° = 8°49'13″ = 2.98876479891 rad
∠ C' = γ' = 175.3654536573° = 175°21'52″ = 0.08109040992 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     