Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 16.55329453572   b = 19.02662975904   c = 7.21111025509

Area: T = 59
Perimeter: p = 42.79903454986
Semiperimeter: s = 21.39551727493

Angle ∠ A = α = 59.32327199782° = 59°19'22″ = 1.03553767849 rad
Angle ∠ B = β = 98.67331740479° = 98°40'23″ = 1.72221717705 rad
Angle ∠ C = γ = 22.00441059739° = 22°15″ = 0.38440440982 rad

Height: ha = 7.12986407013
Height: hb = 6.20219423085
Height: hc = 16.36436557886

Median: ma = 11.76986022959
Median: mb = 8.5154693183
Median: mc = 17.46442491966

Inradius: r = 2.75876313915
Circumradius: R = 9.62331938765

Vertex coordinates: A[-9; -6] B[-5; 0] C[10; -7]
Centroid: CG[-1.33333333333; -4.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0.4210655636; 2.75876313915]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 120.6777280022° = 120°40'38″ = 1.03553767849 rad
∠ B' = β' = 81.32768259521° = 81°19'37″ = 1.72221717705 rad
∠ C' = γ' = 157.9965894026° = 157°59'45″ = 0.38440440982 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     