# 19 25 30 triangle

### Acute scalene triangle.

Sides: a = 19   b = 25   c = 30

Area: T = 236.5254840133
Perimeter: p = 74
Semiperimeter: s = 37

Angle ∠ A = α = 39.10442158089° = 39°6'15″ = 0.68224973173 rad
Angle ∠ B = β = 56.09896705572° = 56°5'23″ = 0.97989494276 rad
Angle ∠ C = γ = 84.80661136338° = 84°48'22″ = 1.48801459087 rad

Height: ha = 24.8977351593
Height: hb = 18.92219872106
Height: hc = 15.76883226755

Median: ma = 25.92877843249
Median: mb = 21.77772817404
Median: mc = 16.37107055437

Inradius: r = 6.39325632468
Circumradius: R = 15.06218429675

Vertex coordinates: A[30; 0] B[0; 0] C[10.6; 15.76883226755]
Centroid: CG[13.53333333333; 5.25661075585]
Coordinates of the circumscribed circle: U[15; 1.36334931528]
Coordinates of the inscribed circle: I[12; 6.39325632468]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 140.8965784191° = 140°53'45″ = 0.68224973173 rad
∠ B' = β' = 123.9110329443° = 123°54'37″ = 0.97989494276 rad
∠ C' = γ' = 95.19438863662° = 95°11'38″ = 1.48801459087 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    