Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 12.36993168769   b = 8.06222577483   c = 8.944427191

Area: T = 36
Perimeter: p = 29.37658465352
Semiperimeter: s = 14.68879232676

Angle ∠ A = α = 93.18798301199° = 93°10'47″ = 1.6266294832 rad
Angle ∠ B = β = 40.6011294645° = 40°36'5″ = 0.70986262721 rad
Angle ∠ C = γ = 46.21988752351° = 46°13'8″ = 0.80766715494 rad

Height: ha = 5.82108550009
Height: hb = 8.93105008904
Height: hc = 8.0549844719

Median: ma = 5.85223499554
Median: mb = 10.01224921973
Median: mc = 9.43439811321

Inradius: r = 2.45109931965
Circumradius: R = 6.19441953114

Vertex coordinates: A[-7; 2] B[-3; 10] C[0; -2]
Centroid: CG[-3.33333333333; 3.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[2.85994920626; 2.45109931965]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 86.82201698801° = 86°49'13″ = 1.6266294832 rad
∠ B' = β' = 139.3998705355° = 139°23'55″ = 0.70986262721 rad
∠ C' = γ' = 133.7811124765° = 133°46'52″ = 0.80766715494 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     