Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 9.43439811321   b = 7.21111025509   c = 4.12331056256

Area: T = 14
Perimeter: p = 20.76881893086
Semiperimeter: s = 10.38440946543

Angle ∠ A = α = 109.6543824058° = 109°39'14″ = 1.91438202672 rad
Angle ∠ B = β = 46.0421626676° = 46°2'30″ = 0.80435779785 rad
Angle ∠ C = γ = 24.30545492659° = 24°18'16″ = 0.42441944079 rad

Height: ha = 2.9687994064
Height: hb = 3.88329013736
Height: hc = 6.7910997501

Median: ma = 3.5
Median: mb = 6.32545553203
Median: mc = 8.1399410298

Vertex coordinates: A[1; 2; 0] B[3; 0; -3] C[5; 2; 6]
Centroid: CG[3; 1.33333333333; 1]
Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 70.34661759419° = 70°20'46″ = 1.91438202672 rad
∠ B' = β' = 133.9588373324° = 133°57'30″ = 0.80435779785 rad
∠ C' = γ' = 155.6955450734° = 155°41'44″ = 0.42441944079 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    