Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 5.65768542495   b = 2.23660679775   c = 3.60655512755

Area: T = 2
Perimeter: p = 11.49884735025
Semiperimeter: s = 5.74992367512

Angle ∠ A = α = 150.2555118703° = 150°15'18″ = 2.62224465393 rad
Angle ∠ B = β = 11.3109932474° = 11°18'36″ = 0.19773955598 rad
Angle ∠ C = γ = 18.43549488229° = 18°26'6″ = 0.32217505544 rad

Height: ha = 0.70771067812
Height: hb = 1.7898854382
Height: hc = 1.10994003925

Median: ma = 1
Median: mb = 4.61097722286
Median: mc = 3.9055124838

Inradius: r = 0.34878722631
Circumradius: R = 5.70108771255

Vertex coordinates: A[0; 0] B[-2; 3] C[2; -1]
Centroid: CG[0; 0.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[1.73993613157; 0.34878722631]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 29.74548812969° = 29°44'42″ = 2.62224465393 rad
∠ B' = β' = 168.6990067526° = 168°41'24″ = 0.19773955598 rad
∠ C' = γ' = 161.5655051177° = 161°33'54″ = 0.32217505544 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     