Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 2.23660679775   b = 7.81102496759   c = 5.65768542495

Area: T = 2
Perimeter: p = 15.70331719029
Semiperimeter: s = 7.85215859514

Angle ∠ A = α = 5.19444289077° = 5°11'40″ = 0.09106598872 rad
Angle ∠ B = β = 161.5655051177° = 161°33'54″ = 2.82198420992 rad
Angle ∠ C = γ = 13.24105199152° = 13°14'26″ = 0.23110906672 rad

Height: ha = 1.7898854382
Height: hb = 0.51221475197
Height: hc = 0.70771067812

Median: ma = 6.72768120235
Median: mb = 1.80327756377
Median: mc = 5

Vertex coordinates: A[0; 3] B[4; 7] C[5; 9]
Centroid: CG[3; 6.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0.7644176822; 0.25547256073]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 174.8065571092° = 174°48'20″ = 0.09106598872 rad
∠ B' = β' = 18.43549488229° = 18°26'6″ = 2.82198420992 rad
∠ C' = γ' = 166.7599480085° = 166°45'34″ = 0.23110906672 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    