# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse scalene triangle.

Sides: a = 13.03884048104   b = 15.65224758425   c = 8.06222577483

Area: T = 52.5
Perimeter: p = 36.75331384012
Semiperimeter: s = 18.37765692006

Angle ∠ A = α = 56.3109932474° = 56°18'36″ = 0.98327937232 rad
Angle ∠ B = β = 92.72663109939° = 92°43'35″ = 1.61883794301 rad
Angle ∠ C = γ = 30.96437565321° = 30°57'50″ = 0.54404195003 rad

Height: ha = 8.05331323829
Height: hb = 6.70882039325
Height: hc = 13.02436471319

Median: ma = 10.60766017178
Median: mb = 7.5
Median: mc = 13.82993166859

Inradius: r = 2.85768988818
Circumradius: R = 7.83551061824

Vertex coordinates: A[7; 1] B[0; 5] C[-7; -6]
Centroid: CG[0; 0]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0.13660428039; 2.85768988818]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 123.6990067526° = 123°41'24″ = 0.98327937232 rad
∠ B' = β' = 87.27436890061° = 87°16'25″ = 1.61883794301 rad
∠ C' = γ' = 149.0366243468° = 149°2'10″ = 0.54404195003 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    