Triangle calculator VC

Please enter the coordinates of the three vertices

Equilateral triangle.

Sides: a = 1.41442135624   b = 1.41442135624   c = 1.41442135624

Area: T = 0.86660254038
Perimeter: p = 4.24326406871
Semiperimeter: s = 2.12113203436

Angle ∠ A = α = 60° = 1.04771975512 rad
Angle ∠ B = β = 60° = 1.04771975512 rad
Angle ∠ C = γ = 60° = 1.04771975512 rad

Height: ha = 1.22547448714
Height: hb = 1.22547448714
Height: hc = 1.22547448714

Median: ma = 1.22547448714
Median: mb = 1.22547448714
Median: mc = 1.22547448714

Inradius: r = 0.40882482905
Circumradius: R = 0.81664965809

Vertex coordinates: A[1; 0; 0] B[0; 1; 0] C[0; 0; 1]
Centroid: CG[0.33333333333; 0.33333333333; 0.33333333333]
Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 120° = 1.04771975512 rad
∠ B' = β' = 120° = 1.04771975512 rad
∠ C' = γ' = 120° = 1.04771975512 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     