# 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 = 36.891   b = 36.891   c = 36.891

Area: T = 589.3076853061
Perimeter: p = 110.673
Semiperimeter: s = 55.33765

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

Height: ha = 31.9498543171
Height: hb = 31.9498543171
Height: hc = 31.9498543171

Median: ma = 31.9498543171
Median: mb = 31.9498543171
Median: mc = 31.9498543171

Inradius: r = 10.65495143903
Circumradius: R = 21.29990287807

Vertex coordinates: A[36.891; 0] B[0; 0] C[18.44655; 31.9498543171]
Centroid: CG[18.44655; 10.65495143903]
Coordinates of the circumscribed circle: U[18.44655; 10.65495143903]
Coordinates of the inscribed circle: I[18.44655; 10.65495143903]

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 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 ### 8. Inradius ### 9. Circumradius ### 10. 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.