Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 13.45436240471   b = 6.70882039325   c = 7.61657731059

Area: T = 16.5
Perimeter: p = 27.77876010854
Semiperimeter: s = 13.88988005427

Angle ∠ A = α = 139.7643641691° = 139°45'49″ = 2.43993357221 rad
Angle ∠ B = β = 18.78986219822° = 18°47'19″ = 0.32879233155 rad
Angle ∠ C = γ = 21.44877363271° = 21°26'52″ = 0.3744333616 rad

Height: ha = 2.45328706826
Height: hb = 4.91993495505
Height: hc = 4.33331122844

Median: ma = 2.5
Median: mb = 10.40443260233
Median: mc = 9.92547166206

Inradius: r = 1.18880075568
Circumradius: R = 10.41439528145

Vertex coordinates: A[0; -3] B[-3; 4] C[6; -6]
Centroid: CG[1; -1.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[3.49220222125; 1.18880075568]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 40.23663583093° = 40°14'11″ = 2.43993357221 rad
∠ B' = β' = 161.2111378018° = 161°12'41″ = 0.32879233155 rad
∠ C' = γ' = 158.5522263673° = 158°33'8″ = 0.3744333616 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     