# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse scalene triangle.

Sides: a = 10.19880390272   b = 12.04215945788   c = 3.60655512755

Area: T = 17
Perimeter: p = 25.84551848814
Semiperimeter: s = 12.92325924407

Angle ∠ A = α = 51.54662907833° = 51°32'47″ = 0.98996524914 rad
Angle ∠ B = β = 112.3880135052° = 112°22'49″ = 1.96114033705 rad
Angle ∠ C = γ = 16.07435741647° = 16°4'25″ = 0.28105367917 rad

Height: ha = 3.33439742973
Height: hb = 2.8243546315
Height: hc = 9.43299033358

Median: ma = 7.28801098893
Median: mb = 4.7176990566
Median: mc = 11.01113577728

Inradius: r = 1.31655255091
Circumradius: R = 6.51112359634

Vertex coordinates: A[-9; 2] B[-7; -1] C[3; 1]
Centroid: CG[-4.33333333333; 0.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0.54216869744; 1.31655255091]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 128.4543709217° = 128°27'13″ = 0.98996524914 rad
∠ B' = β' = 67.6219864948° = 67°37'11″ = 1.96114033705 rad
∠ C' = γ' = 163.9266425835° = 163°55'35″ = 0.28105367917 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    