12 13 19 triangle
Obtuse scalene triangle.
Sides: a = 12 b = 13 c = 19Area: T = 77.0711395472
Perimeter: p = 44
Semiperimeter: s = 22
Angle ∠ A = α = 38.61332185386° = 38°36'48″ = 0.67439277983 rad
Angle ∠ B = β = 42.5376898363° = 42°32'13″ = 0.742240893 rad
Angle ∠ C = γ = 98.85498830984° = 98°51' = 1.72552559253 rad
Height: ha = 12.84552325787
Height: hb = 11.85771377649
Height: hc = 8.11327784707
Median: ma = 15.13327459504
Median: mb = 14.5
Median: mc = 8.1399410298
Inradius: r = 3.50332452487
Circumradius: R = 9.61444619604
Vertex coordinates: A[19; 0] B[0; 0] C[8.84221052632; 8.11327784707]
Centroid: CG[9.28107017544; 2.70442594902]
Coordinates of the circumscribed circle: U[9.5; -1.47991479939]
Coordinates of the inscribed circle: I[9; 3.50332452487]
Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 141.3876781461° = 141°23'12″ = 0.67439277983 rad
∠ B' = β' = 137.4633101637° = 137°27'47″ = 0.742240893 rad
∠ C' = γ' = 81.15501169016° = 81°9' = 1.72552559253 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
