Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 11.04553610172   b = 5.65768542495   c = 8.6022325267

Area: T = 24
Perimeter: p = 25.30545405337
Semiperimeter: s = 12.65222702669

Angle ∠ A = α = 99.4622322208° = 99°27'44″ = 1.73659450042 rad
Angle ∠ B = β = 30.34332488842° = 30°20'36″ = 0.53295895988 rad
Angle ∠ C = γ = 50.19444289077° = 50°11'40″ = 0.87660580506 rad

Height: ha = 4.346571581
Height: hb = 8.48552813742
Height: hc = 5.58798866597

Median: ma = 4.74334164903
Median: mb = 9.48768329805
Median: mc = 7.64985292704

Inradius: r = 1.89768927705
Circumradius: R = 5.59988590107

Vertex coordinates: A[1; -1] B[-4; 6] C[-3; -5]
Centroid: CG[-2; 0]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[3.24105251497; 1.89768927705]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 80.5387677792° = 80°32'16″ = 1.73659450042 rad
∠ B' = β' = 149.6576751116° = 149°39'24″ = 0.53295895988 rad
∠ C' = γ' = 129.8065571092° = 129°48'20″ = 0.87660580506 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     