Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 8.944427191   b = 13.34216640641   c = 5.09990195136

Area: T = 14
Perimeter: p = 27.38549554877
Semiperimeter: s = 13.69224777439

Angle ∠ A = α = 24.30545492659° = 24°18'16″ = 0.42441944079 rad
Angle ∠ B = β = 142.1255016349° = 142°7'30″ = 2.48105494847 rad
Angle ∠ C = γ = 13.57704343852° = 13°34'14″ = 0.23768487609 rad

Height: ha = 3.13304951685
Height: hb = 2.09986887292
Height: hc = 5.49112517839

Median: ma = 9.05553851381
Median: mb = 2.91554759474
Median: mc = 11.06879718106

Inradius: r = 1.02224592117
Circumradius: R = 10.86655982113

Vertex coordinates: A[-9; -6] B[-4; -5] C[4; -9]
Centroid: CG[-3; -6.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-1.3154590415; 1.02224592117]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 155.6955450734° = 155°41'44″ = 0.42441944079 rad
∠ B' = β' = 37.87549836511° = 37°52'30″ = 2.48105494847 rad
∠ C' = γ' = 166.4329565615° = 166°25'46″ = 0.23768487609 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     