Triangle calculator SSS - result

Please enter the triangle sides:

Acute isosceles triangle.

Sides: a = 16   b = 18   c = 18

Area: T = 128.9966123973
Perimeter: p = 52
Semiperimeter: s = 26

Angle ∠ A = α = 52.77655999225° = 52°46'32″ = 0.92111079834 rad
Angle ∠ B = β = 63.61222000388° = 63°36'44″ = 1.11102423351 rad
Angle ∠ C = γ = 63.61222000388° = 63°36'44″ = 1.11102423351 rad

Height: ha = 16.12545154966
Height: hb = 14.33329026636
Height: hc = 14.33329026636

Median: ma = 16.12545154966
Median: mb = 14.45768322948
Median: mc = 14.45768322948

Inradius: r = 4.96113893836
Circumradius: R = 10.04768135017

Vertex coordinates: A[18; 0] B[0; 0] C[7.11111111111; 14.33329026636]
Centroid: CG[8.37703703704; 4.77876342212]
Coordinates of the circumscribed circle: U[9; 4.46552504452]
Coordinates of the inscribed circle: I[8; 4.96113893836]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 127.2244400078° = 127°13'28″ = 0.92111079834 rad
∠ B' = β' = 116.3887799961° = 116°23'16″ = 1.11102423351 rad
∠ C' = γ' = 116.3887799961° = 116°23'16″ = 1.11102423351 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     