# 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 = 108   b = 108   c = 108

Area: T = 5050.666015487
Perimeter: p = 324
Semiperimeter: s = 162

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

Height: ha = 93.53107436087
Height: hb = 93.53107436087
Height: hc = 93.53107436087

Median: ma = 93.53107436087
Median: mb = 93.53107436087
Median: mc = 93.53107436087

Inradius: r = 31.17769145362
Circumradius: R = 62.35438290725

Vertex coordinates: A[108; 0] B[0; 0] C[54; 93.53107436087]
Centroid: CG[54; 31.17769145362]
Coordinates of the circumscribed circle: U[54; 31.17769145362]
Coordinates of the inscribed circle: I[54; 31.17769145362]

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). 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. ### 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 ### 7. Inradius ### 8. Circumradius ### 9. 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.