# Triangle calculator SSS - result

Please enter the triangle sides:

### Equilateral triangle.

Sides: a = 13.51   b = 13.51   c = 13.51

Area: T = 79.03435216506
Perimeter: p = 40.53
Semiperimeter: s = 20.265

Angle ∠ A = α = 60° = 1.04771975512 rad
Angle ∠ B = β = 60° = 1.04771975512 rad
Angle ∠ C = γ = 60° = 1.04771975512 rad

Height: ha = 11.77000032051
Height: hb = 11.77000032051
Height: hc = 11.77000032051

Median: ma = 11.77000032051
Median: mb = 11.77000032051
Median: mc = 11.77000032051

Inradius: r = 3.99000010684
Circumradius: R = 7.88000021368

Vertex coordinates: A[13.51; 0] B[0; 0] C[6.755; 11.77000032051]
Centroid: CG[6.755; 3.99000010684]
Coordinates of the circumscribed circle: U[6.755; 3.99000010684]
Coordinates of the inscribed circle: I[6.755; 3.99000010684]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 120° = 1.04771975512 rad
∠ B' = β' = 120° = 1.04771975512 rad
∠ C' = γ' = 120° = 1.04771975512 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    