Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 6.32545553203   b = 9.22195444573   c = 15.52441746963

Area: T = 3
Perimeter: p = 31.06882744739
Semiperimeter: s = 15.53441372369

Angle ∠ A = α = 2.4032609469° = 2°24'9″ = 0.04219334459 rad
Angle ∠ B = β = 3.50435316448° = 3°30'13″ = 0.06111481626 rad
Angle ∠ C = γ = 174.0943858886° = 174°5'38″ = 3.03985110451 rad

Height: ha = 0.94986832981
Height: hb = 0.65107913735
Height: hc = 0.38664939758

Median: ma = 12.36993168769
Median: mb = 10.92201648339
Median: mc = 1.5

Inradius: r = 0.19331230524
Circumradius: R = 75.43439298842

Vertex coordinates: A[1; -9] B[5; 6] C[3; 0]
Centroid: CG[3; -1]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[3.15443431896; 0.19331230524]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 177.5977390531° = 177°35'51″ = 0.04219334459 rad
∠ B' = β' = 176.4966468355° = 176°29'47″ = 0.06111481626 rad
∠ C' = γ' = 5.90661411138° = 5°54'22″ = 3.03985110451 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     