# Equilateral triangle calculator

Please enter one property of the equilateral triangle

Use symbols: a, h, T, p, r, R

You have entered side a, b and c (as equilateral triangle).

### Equilateral triangle.

Sides: a = 23792379   b = 23792379   c = 23792379

Area: T = 2.45118660495E+14
Perimeter: p = 71377137
Semiperimeter: s = 35688568.5

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

Height: ha = 20604804.63305
Height: hb = 20604804.63305
Height: hc = 20604804.63305

Median: ma = 20604804.63305
Median: mb = 20604804.63305
Median: mc = 20604804.63305

Inradius: r = 6868268.211016
Circumradius: R = 13736536.42203

Vertex coordinates: A[23792379; 0] B[0; 0] C[11896189.5; 20604804.63305]
Centroid: CG[11896189.5; 6868268.211016]
Coordinates of the circumscribed circle: U[11896189.5; 6868268.211016]
Coordinates of the inscribed circle: I[11896189.5; 6868268.211016]

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. From we calculate b,c: 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. ### 3. The triangle circumference is the sum of the lengths of its three sides ### 4. Semiperimeter of the triangle ### 5. The triangle area using Heron's formula ### 6. Calculate the heights of the triangle from its area. ### 7. Calculation of the inner angles of the triangle using a Law of Cosines    