Triangle calculator VC

Please enter the coordinates of the three vertices

Acute scalene triangle.

Sides: a = 21.2088267256   b = 36.51107285602   c = 33.72880817717

Area: T = 351.965953403
Perimeter: p = 91.44770775879
Semiperimeter: s = 45.7243538794

Angle ∠ A = α = 34.86435623162° = 34°51'49″ = 0.60884839514 rad
Angle ∠ B = β = 79.75993720006° = 79°45'34″ = 1.39220636507 rad
Angle ∠ C = γ = 65.37770656832° = 65°22'37″ = 1.14110450515 rad

Height: ha = 33.19107863837
Height: hb = 19.28797869508
Height: hc = 20.87704151284

Median: ma = 33.50991144317
Median: mb = 21.45876029649
Median: mc = 24.63876962194

Inradius: r = 7.69875567358
Circumradius: R = 18.55108837331

Vertex coordinates: A[-35.47; 12.78; 55.65] B[-10.68; -2.35; 38.5] C[-7.81; 17.74; 32.34]
Centroid: CG[-17.98766666667; 9.39; 42.16333333333]
Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 145.1366437684° = 145°8'11″ = 0.60884839514 rad
∠ B' = β' = 100.2410627999° = 100°14'26″ = 1.39220636507 rad
∠ C' = γ' = 114.6232934317° = 114°37'23″ = 1.14110450515 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     