Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 5.38551648071   b = 2.44994897428   c = 4.12331056256

Area: T = 4.82218253805
Perimeter: p = 11.95877601755
Semiperimeter: s = 5.97988800878

Angle ∠ A = α = 107.288016089° = 107°16'49″ = 1.87223920296 rad
Angle ∠ B = β = 25.7432553049° = 25°44'33″ = 0.44992923086 rad
Angle ∠ C = γ = 46.9777286061° = 46°58'38″ = 0.82199083154 rad

Height: ha = 1.79107809893
Height: hb = 3.9377003937
Height: hc = 2.33989288649

Median: ma = 2.06215528128
Median: mb = 4.63768092477
Median: mc = 3.64400549446

Inradius: r = 0.80664763484
Circumradius: R = 2.82198604404

Vertex coordinates: A[0; 1; 1] B[-2; 4; 3] C[1; 2; -1]
Centroid: CG[-0.33333333333; 2.33333333333; 1]
Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 72.721983911° = 72°43'11″ = 1.87223920296 rad
∠ B' = β' = 154.2577446951° = 154°15'27″ = 0.44992923086 rad
∠ C' = γ' = 133.0232713939° = 133°1'22″ = 0.82199083154 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     