# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse scalene triangle.

Sides: a = 13.45436240471   b = 6.70882039325   c = 7.61657731059

Area: T = 16.5
Perimeter: p = 27.77876010854
Semiperimeter: s = 13.88988005427

Angle ∠ A = α = 139.7643641691° = 139°45'49″ = 2.43993357221 rad
Angle ∠ B = β = 18.78986219822° = 18°47'19″ = 0.32879233155 rad
Angle ∠ C = γ = 21.44877363271° = 21°26'52″ = 0.3744333616 rad

Height: ha = 2.45328706826
Height: hb = 4.91993495505
Height: hc = 4.33331122844

Median: ma = 2.5
Median: mb = 10.40443260233
Median: mc = 9.92547166206

Inradius: r = 1.18880075568
Circumradius: R = 10.41439528145

Vertex coordinates: A[0; -3] B[-3; 4] C[6; -6]
Centroid: CG[1; -1.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[3.49220222125; 1.18880075568]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 40.23663583093° = 40°14'11″ = 2.43993357221 rad
∠ B' = β' = 161.2111378018° = 161°12'41″ = 0.32879233155 rad
∠ C' = γ' = 158.5522263673° = 158°33'8″ = 0.3744333616 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    