# 10 23 28 triangle

### Obtuse scalene triangle.

Sides: a = 10   b = 23   c = 28

Area: T = 108.2754823943
Perimeter: p = 61
Semiperimeter: s = 30.5

Angle ∠ A = α = 19.64990068155° = 19°38'56″ = 0.34329398637 rad
Angle ∠ B = β = 50.65994361643° = 50°39'34″ = 0.88441739583 rad
Angle ∠ C = γ = 109.692155702° = 109°41'30″ = 1.91444788316 rad

Height: ha = 21.65549647887
Height: hb = 9.4155202082
Height: hc = 7.7343915996

Median: ma = 25.13296637463
Median: mb = 17.65997159068
Median: mc = 10.88657705285

Inradius: r = 3.55499942277
Circumradius: R = 14.87695693178

Vertex coordinates: A[28; 0] B[0; 0] C[6.33992857143; 7.7343915996]
Centroid: CG[11.44664285714; 2.57879719987]
Coordinates of the circumscribed circle: U[14; -5.01103983571]
Coordinates of the inscribed circle: I[7.5; 3.55499942277]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 160.3510993185° = 160°21'4″ = 0.34329398637 rad
∠ B' = β' = 129.3410563836° = 129°20'26″ = 0.88441739583 rad
∠ C' = γ' = 70.30884429798° = 70°18'30″ = 1.91444788316 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    