Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 31.95330906173   b = 35.60989876295   c = 11.18803398875

Area: T = 176
Perimeter: p = 78.74224181344
Semiperimeter: s = 39.37112090672

Angle ∠ A = α = 62.14876198814° = 62°8'51″ = 1.08546805892 rad
Angle ∠ B = β = 99.83114569595° = 99°49'53″ = 1.7422387621 rad
Angle ∠ C = γ = 18.02109231591° = 18°1'15″ = 0.31545244434 rad

Height: ha = 11.01661487731
Height: hb = 9.88551448309
Height: hc = 31.48438371232

Median: ma = 21.00659515376
Median: mb = 16
Median: mc = 33.36554012414

Inradius: r = 4.47702716571
Circumradius: R = 18.07698623879

Vertex coordinates: A[11; 4] B[13; -7] C[-17; -18]
Centroid: CG[2.33333333333; -7]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0.77546777588; 4.47702716571]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 117.8522380119° = 117°51'9″ = 1.08546805892 rad
∠ B' = β' = 80.16985430405° = 80°10'7″ = 1.7422387621 rad
∠ C' = γ' = 161.9799076841° = 161°58'45″ = 0.31545244434 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     