# Equilateral triangle calculator (S)

Please enter one property of the equilateral triangle

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

You have entered area S.

### Equilateral triangle.

Sides: a = 13.50771345986   b = 13.50771345986   c = 13.50771345986

Area: T = 79
Perimeter: p = 40.52114037957
Semiperimeter: s = 20.26107018979

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

Height: ha = 11.69875216947
Height: hb = 11.69875216947
Height: hc = 11.69875216947

Median: ma = 11.69875216947
Median: mb = 11.69875216947
Median: mc = 11.69875216947

Inradius: r = 3.89991738982
Circumradius: R = 7.79883477965

Vertex coordinates: A[13.50771345986; 0] B[0; 0] C[6.75435672993; 11.69875216947]
Centroid: CG[6.75435672993; 3.89991738982]
Coordinates of the circumscribed circle: U[6.75435672993; 3.89991738982]
Coordinates of the inscribed circle: I[6.75435672993; 3.89991738982]

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: area S ### 2. From area S we calculate side a: ### 3. From side a 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. ### 4. The triangle circumference is the sum of the lengths of its three sides ### 5. Semiperimeter of the triangle ### 6. The triangle area using Heron's formula ### 7. Calculate the heights of the triangle from its area. ### 8. Calculation of the inner angles of the triangle using a Law of Cosines ### 9. Inradius ### 10. Circumradius ### 11. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.