# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse scalene triangle.

Sides: a = 7.07110678119   b = 8.54440037453   c = 3.60655512755

Area: T = 12.5
Perimeter: p = 19.22106228326
Semiperimeter: s = 9.61103114163

Angle ∠ A = α = 54.24661127456° = 54°14'46″ = 0.94767732738 rad
Angle ∠ B = β = 101.3109932474° = 101°18'36″ = 1.76881918866 rad
Angle ∠ C = γ = 24.44439547804° = 24°26'38″ = 0.42766274931 rad

Height: ha = 3.53655339059
Height: hb = 2.92660286799
Height: hc = 6.93437524528

Median: ma = 5.52326805086
Median: mb = 3.64400549446
Median: mc = 7.63221687612

Inradius: r = 1.30106862586
Circumradius: R = 4.35766041822

Vertex coordinates: A[2; 7] B[4; 4] C[-1; -1]
Centroid: CG[1.66766666667; 3.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0.26601372517; 1.30106862586]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 125.7543887254° = 125°45'14″ = 0.94767732738 rad
∠ B' = β' = 78.6990067526° = 78°41'24″ = 1.76881918866 rad
∠ C' = γ' = 155.556604522° = 155°33'22″ = 0.42766274931 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    