Triangle calculator SSS - result

Please enter the triangle sides:

Obtuse scalene triangle.

Sides: a = 5   b = 16   c = 20

Area: T = 26.7388315205
Perimeter: p = 41
Semiperimeter: s = 20.5

Angle ∠ A = α = 9.62200904201° = 9°37'12″ = 0.16879022522 rad
Angle ∠ B = β = 32.32880641222° = 32°19'41″ = 0.56442311597 rad
Angle ∠ C = γ = 138.0521845458° = 138°3'7″ = 2.40994592417 rad

Height: ha = 10.6955326082
Height: hb = 3.34222894006
Height: hc = 2.67438315205

Median: ma = 17.93773911147
Median: mb = 12.1866057607
Median: mc = 6.36439610307

Inradius: r = 1.30443080588
Circumradius: R = 14.96598056921

Vertex coordinates: A[20; 0] B[0; 0] C[4.225; 2.67438315205]
Centroid: CG[8.075; 0.89112771735]
Coordinates of the circumscribed circle: U[10; -11.12663554835]
Coordinates of the inscribed circle: I[4.5; 1.30443080588]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 170.387990958° = 170°22'48″ = 0.16879022522 rad
∠ B' = β' = 147.6721935878° = 147°40'19″ = 0.56442311597 rad
∠ C' = γ' = 41.94881545423° = 41°56'53″ = 2.40994592417 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     