# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse scalene triangle.

Sides: a = 9.43439811321   b = 32.38882694814   c = 40

Area: T = 100
Perimeter: p = 81.82222506135
Semiperimeter: s = 40.91111253067

Angle ∠ A = α = 8.88106591505° = 8°52'50″ = 0.15549967419 rad
Angle ∠ B = β = 32.00553832081° = 32°19″ = 0.55985993153 rad
Angle ∠ C = γ = 139.1143957641° = 139°6'50″ = 2.42879965963 rad

Height: ha = 21.21999576001
Height: hb = 6.17550752109
Height: hc = 5

Median: ma = 36.08767011515
Median: mb = 24.1329857024
Median: mc = 13

Vertex coordinates: A[-21; 0] B[19; 0] C[11; -5]
Centroid: CG[3; -1.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[3.91109166223; 2.4444322889]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 171.1199340849° = 171°7'10″ = 0.15549967419 rad
∠ B' = β' = 147.9954616792° = 147°59'41″ = 0.55985993153 rad
∠ C' = γ' = 40.88660423586° = 40°53'10″ = 2.42879965963 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    