Triangle calculator SSS - result

Please enter the triangle sides:

Acute isosceles triangle.

Sides: a = 7   b = 7   c = 9

Area: T = 24.12985619132
Perimeter: p = 23
Semiperimeter: s = 11.5

Angle ∠ A = α = 49.99547991151° = 49°59'41″ = 0.87325738534 rad
Angle ∠ B = β = 49.99547991151° = 49°59'41″ = 0.87325738534 rad
Angle ∠ C = γ = 80.01104017697° = 80°37″ = 1.39664449467 rad

Height: ha = 6.89438748323
Height: hb = 6.89438748323
Height: hc = 5.36219026474

Median: ma = 7.26329195232
Median: mb = 7.26329195232
Median: mc = 5.36219026474

Inradius: r = 2.09881358185
Circumradius: R = 4.56992735604

Vertex coordinates: A[9; 0] B[0; 0] C[4.5; 5.36219026474]
Centroid: CG[4.5; 1.78773008825]
Coordinates of the circumscribed circle: U[4.5; 0.7932629087]
Coordinates of the inscribed circle: I[4.5; 2.09881358185]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 130.0055200885° = 130°19″ = 0.87325738534 rad
∠ B' = β' = 130.0055200885° = 130°19″ = 0.87325738534 rad
∠ C' = γ' = 99.99895982303° = 99°59'23″ = 1.39664449467 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    