Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 12.64991106407   b = 5.65768542495   c = 17.889854382

Area: T = 16
Perimeter: p = 36.19545087102
Semiperimeter: s = 18.09772543551

Angle ∠ A = α = 18.43549488229° = 18°26'6″ = 0.32217505544 rad
Angle ∠ B = β = 8.13301023542° = 8°7'48″ = 0.14218970546 rad
Angle ∠ C = γ = 153.4354948823° = 153°26'6″ = 2.67879450446 rad

Height: ha = 2.53298221281
Height: hb = 5.65768542495
Height: hc = 1.7898854382

Median: ma = 11.66219037897
Median: mb = 15.23215462117
Median: mc = 4

Inradius: r = 0.88441120142
Circumradius: R = 20

Vertex coordinates: A[-10; -3] B[6; 5] C[-6; 1]
Centroid: CG[-3.33333333333; 1]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[6.18987840996; 0.88441120142]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.5655051177° = 161°33'54″ = 0.32217505544 rad
∠ B' = β' = 171.8769897646° = 171°52'12″ = 0.14218970546 rad
∠ C' = γ' = 26.56550511771° = 26°33'54″ = 2.67879450446 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     