# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse scalene triangle.

Sides: a = 12.64991106407   b = 5.65768542495   c = 17.889854382

Area: T = 16
Perimeter: p = 36.19545087102
Semiperimeter: s = 18.09772543551

Angle ∠ A = α = 18.43549488229° = 18°26'6″ = 0.32217505544 rad
Angle ∠ B = β = 8.13301023542° = 8°7'48″ = 0.14218970546 rad
Angle ∠ C = γ = 153.4354948823° = 153°26'6″ = 2.67879450446 rad

Height: ha = 2.53298221281
Height: hb = 5.65768542495
Height: hc = 1.7898854382

Median: ma = 11.66219037897
Median: mb = 15.23215462117
Median: mc = 4

Inradius: r = 0.88441120142
Circumradius: R = 20

Vertex coordinates: A[-10; -3] B[6; 5] C[-6; 1]
Centroid: CG[-3.33333333333; 1]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[6.18987840996; 0.88441120142]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.5655051177° = 161°33'54″ = 0.32217505544 rad
∠ B' = β' = 171.8769897646° = 171°52'12″ = 0.14218970546 rad
∠ C' = γ' = 26.56550511771° = 26°33'54″ = 2.67879450446 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    