# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse scalene triangle.

Sides: a = 8.48552813742   b = 21.09550231097   c = 27.29546881279

Area: T = 69
Perimeter: p = 56.87549926119
Semiperimeter: s = 28.43774963059

Angle ∠ A = α = 13.86773010525° = 13°52'2″ = 0.24220300617 rad
Angle ∠ B = β = 36.57330309785° = 36°34'23″ = 0.6388319808 rad
Angle ∠ C = γ = 129.5659667969° = 129°33'35″ = 2.26112427838 rad

Height: ha = 16.26334559673
Height: hb = 6.54218273913
Height: hc = 5.05659288076

Median: ma = 24.02108242989
Median: mb = 17.24109396496
Median: mc = 8.5

Inradius: r = 2.42663739416
Circumradius: R = 17.70217135223

Vertex coordinates: A[-19; -8] B[8; -12] C[2; -6]
Centroid: CG[-3; -8.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[3.27703300951; 2.42663739416]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 166.1332698948° = 166°7'58″ = 0.24220300617 rad
∠ B' = β' = 143.4276969021° = 143°25'37″ = 0.6388319808 rad
∠ C' = γ' = 50.4440332031° = 50°26'25″ = 2.26112427838 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    