Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 10.19880390272   b = 4.4722135955   c = 8.24662112512

Area: T = 18
Perimeter: p = 22.91663862334
Semiperimeter: s = 11.45881931167

Angle ∠ A = α = 102.5298807709° = 102°31'44″ = 1.78994652727 rad
Angle ∠ B = β = 25.34661759419° = 25°20'46″ = 0.4422374223 rad
Angle ∠ C = γ = 52.12550163489° = 52°7'30″ = 0.91097531579 rad

Height: ha = 3.53300904325
Height: hb = 8.0549844719
Height: hc = 4.36656412507

Median: ma = 4.24326406871
Median: mb = 9
Median: mc = 6.70882039325

Inradius: r = 1.57109283145
Circumradius: R = 5.22334041216

Vertex coordinates: A[-3; 6] B[5; 8] C[-5; 10]
Centroid: CG[-1; 8]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[3.31664042195; 1.57109283145]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 77.47111922908° = 77°28'16″ = 1.78994652727 rad
∠ B' = β' = 154.6543824058° = 154°39'14″ = 0.4422374223 rad
∠ C' = γ' = 127.8754983651° = 127°52'30″ = 0.91097531579 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     