Triangle calculator SSS - result

Please enter the triangle sides:

Obtuse scalene triangle.

Sides: a = 3   b = 7   c = 8

Area: T = 10.39223048454
Perimeter: p = 18
Semiperimeter: s = 9

Angle ∠ A = α = 21.78767892983° = 21°47'12″ = 0.38802512067 rad
Angle ∠ B = β = 60° = 1.04771975512 rad
Angle ∠ C = γ = 98.21332107017° = 98°12'48″ = 1.71441438957 rad

Height: ha = 6.92882032303
Height: hb = 2.96992299558
Height: hc = 2.59880762114

Median: ma = 7.36554599313
Median: mb = 4.92444289009
Median: mc = 3.60655512755

Inradius: r = 1.15547005384
Circumradius: R = 4.04114518843

Vertex coordinates: A[8; 0] B[0; 0] C[1.5; 2.59880762114]
Centroid: CG[3.16766666667; 0.86660254038]
Coordinates of the circumscribed circle: U[4; -0.57773502692]
Coordinates of the inscribed circle: I[2; 1.15547005384]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 158.2133210702° = 158°12'48″ = 0.38802512067 rad
∠ B' = β' = 120° = 1.04771975512 rad
∠ C' = γ' = 81.78767892983° = 81°47'12″ = 1.71441438957 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    