# 8 12 19 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 12   c = 19

Area: T = 28.99989223938
Perimeter: p = 39
Semiperimeter: s = 19.5

Angle ∠ A = α = 14.73766437225° = 14°44'12″ = 0.25772029537 rad
Angle ∠ B = β = 22.43106417388° = 22°25'50″ = 0.39114885517 rad
Angle ∠ C = γ = 142.8332714539° = 142°49'58″ = 2.49329011483 rad

Height: ha = 7.25497305984
Height: hb = 4.83331537323
Height: hc = 3.05325181467

Median: ma = 15.37985564992
Median: mb = 13.28553302556
Median: mc = 3.70880992435

Inradius: r = 1.48771242253
Circumradius: R = 15.72547222434

Vertex coordinates: A[19; 0] B[0; 0] C[7.39547368421; 3.05325181467]
Centroid: CG[8.7988245614; 1.01875060489]
Coordinates of the circumscribed circle: U[9.5; -12.53106380377]
Coordinates of the inscribed circle: I[7.5; 1.48771242253]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 165.2633356278° = 165°15'48″ = 0.25772029537 rad
∠ B' = β' = 157.5699358261° = 157°34'10″ = 0.39114885517 rad
∠ C' = γ' = 37.16772854613° = 37°10'2″ = 2.49329011483 rad

# 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 ### 8. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.