Triangle calculator

Please enter what you know about the triangle:
You have entered side a, b and c (as equilateral triangle).

Equilateral triangle.

Sides: a = 45   b = 45   c = 45

Area: T = 876.8510721332
Perimeter: p = 135
Semiperimeter: s = 67.5

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

Height: ha = 38.97111431703
Height: hb = 38.97111431703
Height: hc = 38.97111431703

Median: ma = 38.97111431703
Median: mb = 38.97111431703
Median: mc = 38.97111431703

Inradius: r = 12.99903810568
Circumradius: R = 25.98107621135

Vertex coordinates: A[45; 0] B[0; 0] C[22.5; 38.97111431703]
Centroid: CG[22.5; 12.99903810568]
Coordinates of the circumscribed circle: U[22.5; 12.99903810568]
Coordinates of the inscribed circle: I[22.5; 12.99903810568]

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. Input data entered: side a, b and c (as equilateral triangle). 2. The triangle circumference is the sum of the lengths of its three sides 3. Semiperimeter of the triangle 4. The triangle area using Heron's formula 5. Calculate the heights of the triangle from its area. 6. Calculation of the inner angles of the triangle using a Law of Cosines    