# 11 24 28 triangle

### Obtuse scalene triangle.

Sides: a = 11   b = 24   c = 28

Area: T = 130.196576606
Perimeter: p = 63
Semiperimeter: s = 31.5

Angle ∠ A = α = 22.79882480997° = 22°47'54″ = 0.3987904493 rad
Angle ∠ B = β = 57.71877199078° = 57°43'4″ = 1.00773642491 rad
Angle ∠ C = γ = 99.48440319925° = 99°29'3″ = 1.73663239114 rad

Height: ha = 23.67219574655
Height: hb = 10.85496471717
Height: hc = 9.32996975757

Median: ma = 25.49901941931
Median: mb = 17.56441680703
Median: mc = 12.34990890352

Inradius: r = 4.13331989225
Circumradius: R = 14.19440099584

Vertex coordinates: A[28; 0] B[0; 0] C[5.875; 9.32996975757]
Centroid: CG[11.29216666667; 3.10998991919]
Coordinates of the circumscribed circle: U[14; -2.33987857318]
Coordinates of the inscribed circle: I[7.5; 4.13331989225]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 157.20217519° = 157°12'6″ = 0.3987904493 rad
∠ B' = β' = 122.2822280092° = 122°16'56″ = 1.00773642491 rad
∠ C' = γ' = 80.51659680075° = 80°30'57″ = 1.73663239114 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    