# Triangle calculator SSS - result

Please enter the triangle sides:

### Acute isosceles triangle.

Sides: a = 5   b = 12   c = 12

Area: T = 29.34217364858
Perimeter: p = 29
Semiperimeter: s = 14.5

Angle ∠ A = α = 24.04993983611° = 24°2'58″ = 0.42197411845 rad
Angle ∠ B = β = 77.97553008194° = 77°58'31″ = 1.36109257345 rad
Angle ∠ C = γ = 77.97553008194° = 77°58'31″ = 1.36109257345 rad

Height: ha = 11.73766945943
Height: hb = 4.89902894143
Height: hc = 4.89902894143

Median: ma = 11.73766945943
Median: mb = 6.96441941386
Median: mc = 6.96441941386

Inradius: r = 2.02435680335
Circumradius: R = 6.13546062489

Vertex coordinates: A[12; 0] B[0; 0] C[1.04216666667; 4.89902894143]
Centroid: CG[4.34772222222; 1.63300964714]
Coordinates of the circumscribed circle: U[6; 1.27880429685]
Coordinates of the inscribed circle: I[2.5; 2.02435680335]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 155.9510601639° = 155°57'2″ = 0.42197411845 rad
∠ B' = β' = 102.0254699181° = 102°1'29″ = 1.36109257345 rad
∠ C' = γ' = 102.0254699181° = 102°1'29″ = 1.36109257345 rad

# How did we calculate this triangle?

### 1. The triangle circumference is the sum of the lengths of its three sides ### 2. Semiperimeter of the triangle ### 3. The triangle area using Heron's formula ### 4. Calculate the heights of the triangle from its area. ### 5. Calculation of the inner angles of the triangle using a Law of Cosines    