Triangle calculator SSS - result

Please enter the triangle sides:

Obtuse isosceles triangle.

Sides: a = 13   b = 13   c = 19

Area: T = 84.30441369092
Perimeter: p = 45
Semiperimeter: s = 22.5

Angle ∠ A = α = 43.04990798002° = 43°2'57″ = 0.75113481825 rad
Angle ∠ B = β = 43.04990798002° = 43°2'57″ = 0.75113481825 rad
Angle ∠ C = γ = 93.90218403995° = 93°54'7″ = 1.63988962887 rad

Height: ha = 12.97698672168
Height: hb = 12.97698672168
Height: hc = 8.87441196746

Median: ma = 14.92548115566
Median: mb = 14.92548115566
Median: mc = 8.87441196746

Inradius: r = 3.74768505293
Circumradius: R = 9.52220712699

Vertex coordinates: A[19; 0] B[0; 0] C[9.5; 8.87441196746]
Centroid: CG[9.5; 2.95880398915]
Coordinates of the circumscribed circle: U[9.5; -0.64879515953]
Coordinates of the inscribed circle: I[9.5; 3.74768505293]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 136.95109202° = 136°57'3″ = 0.75113481825 rad
∠ B' = β' = 136.95109202° = 136°57'3″ = 0.75113481825 rad
∠ C' = γ' = 86.09881596005° = 86°5'53″ = 1.63988962887 rad

How did we calculate this triangle?

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     