40 66 66 triangle

Acute isosceles triangle.

Sides: a = 40   b = 66   c = 66

Area: T = 1257.935481548
Perimeter: p = 172
Semiperimeter: s = 86

Angle ∠ A = α = 35.27994027885° = 35°16'46″ = 0.61657417368 rad
Angle ∠ B = β = 72.36602986058° = 72°21'37″ = 1.26329254584 rad
Angle ∠ C = γ = 72.36602986058° = 72°21'37″ = 1.26329254584 rad

Height: ha = 62.89767407741
Height: hb = 38.11992368328
Height: hc = 38.11992368328

Median: ma = 62.89767407741
Median: mb = 43.46326276242
Median: mc = 43.46326276242

Inradius: r = 14.62771490172
Circumradius: R = 34.62881853908

Vertex coordinates: A[66; 0] B[0; 0] C[12.12112121212; 38.11992368328]
Centroid: CG[26.04404040404; 12.70664122776]
Coordinates of the circumscribed circle: U[33; 10.49333895124]
Coordinates of the inscribed circle: I[20; 14.62771490172]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 144.7210597212° = 144°43'14″ = 0.61657417368 rad
∠ B' = β' = 107.6439701394° = 107°38'23″ = 1.26329254584 rad
∠ C' = γ' = 107.6439701394° = 107°38'23″ = 1.26329254584 rad

How did we calculate this triangle?

Now we know the lengths of all three sides of the triangle and the triangle is uniquely determined. Next we calculate another its characteristics - same procedure as calculation of the triangle from the known three sides SSS. 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     