13 14 21 triangle
Obtuse scalene triangle.
Sides: a = 13 b = 14 c = 21Area: T = 88.99443818451
Perimeter: p = 48
Semiperimeter: s = 24
Angle ∠ A = α = 37.25879160013° = 37°15'29″ = 0.65502733067 rad
Angle ∠ B = β = 40.69105605975° = 40°41'26″ = 0.71101842569 rad
Angle ∠ C = γ = 102.0521523401° = 102°3'5″ = 1.781113509 rad
Height: ha = 13.69114433608
Height: hb = 12.71334831207
Height: hc = 8.47656554138
Median: ma = 16.62107701386
Median: mb = 16
Median: mc = 8.5
Inradius: r = 3.70880992435
Circumradius: R = 10.73766328097
Vertex coordinates: A[21; 0] B[0; 0] C[9.85771428571; 8.47656554138]
Centroid: CG[10.28657142857; 2.82552184713]
Coordinates of the circumscribed circle: U[10.5; -2.24217145427]
Coordinates of the inscribed circle: I[10; 3.70880992435]
Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 142.7422083999° = 142°44'31″ = 0.65502733067 rad
∠ B' = β' = 139.3099439402° = 139°18'34″ = 0.71101842569 rad
∠ C' = γ' = 77.94884765988° = 77°56'55″ = 1.781113509 rad
Calculate another triangle
How did we calculate this triangle?
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.
1. The triangle circumference is the sum of the lengths of its three sides

2. Semiperimeter of the triangle

3. The triangle area using Heron's formula

4. Calculate the heights of the triangle from its area.

5. Calculation of the inner angles of the triangle using a Law of Cosines

6. Inradius

7. Circumradius
