# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse scalene triangle.

Sides: a = 5.38551648071   b = 3.31766247904   c = 2.44994897428

Area: T = 2.73986127875
Perimeter: p = 11.15112793403
Semiperimeter: s = 5.57656396701

Angle ∠ A = α = 137.6087954285° = 137°36'29″ = 2.40217118792 rad
Angle ∠ B = β = 24.53436377129° = 24°32'1″ = 0.42881927556 rad
Angle ∠ C = γ = 17.85884080019° = 17°51'30″ = 0.31216880188 rad

Height: ha = 1.01770952554
Height: hb = 1.65114456477
Height: hc = 2.23660679775

Median: ma = 1.11880339887
Median: mb = 3.84105728739
Median: mc = 4.30111626335

Inradius: r = 0.49111746364
Circumradius: R = 3.99437451095

Vertex coordinates: A[2; 0; 0] B[3; 2; -1] C[3; -3; 1]
Centroid: CG[2.66766666667; -0.33333333333; 0]
Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 42.39220457148° = 42°23'31″ = 2.40217118792 rad
∠ B' = β' = 155.4666362287° = 155°27'59″ = 0.42881927556 rad
∠ C' = γ' = 162.1421591998° = 162°8'30″ = 0.31216880188 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    