Triangle calculator VC

Please enter the coordinates of the three vertices

Acute scalene triangle.

Sides: a = 15.62204993518   b = 16.12545154966   c = 5.65768542495

Area: T = 44
Perimeter: p = 37.40218690979
Semiperimeter: s = 18.7010934549

Angle ∠ A = α = 74.74548812969° = 74°44'42″ = 1.30545442776 rad
Angle ∠ B = β = 84.80655710923° = 84°48'20″ = 1.48801364396 rad
Angle ∠ C = γ = 20.45495476108° = 20°26'58″ = 0.35769119364 rad

Height: ha = 5.6343622717
Height: hb = 5.45875283219
Height: hc = 15.55663491861

Median: ma = 9.22195444573
Median: mb = 8.54440037453
Median: mc = 15.62204993518

Inradius: r = 2.3532823592
Circumradius: R = 8.09655043131

Vertex coordinates: A[-5; 2] B[-1; 6] C[9; -6]
Centroid: CG[1; 0.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[0.21438930538; 2.3532823592]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 105.2555118703° = 105°15'18″ = 1.30545442776 rad
∠ B' = β' = 95.19444289077° = 95°11'40″ = 1.48801364396 rad
∠ C' = γ' = 159.5550452389° = 159°33'2″ = 0.35769119364 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     