# 26 27 27 triangle

### Acute isosceles triangle.

Sides: a = 26   b = 27   c = 27

Area: T = 307.6366148721
Perimeter: p = 80
Semiperimeter: s = 40

Angle ∠ A = α = 57.56444093612° = 57°33'52″ = 1.00546884753 rad
Angle ∠ B = β = 61.21877953194° = 61°13'4″ = 1.06884520891 rad
Angle ∠ C = γ = 61.21877953194° = 61°13'4″ = 1.06884520891 rad

Height: ha = 23.66443191324
Height: hb = 22.78878628682
Height: hc = 22.78878628682

Median: ma = 23.66443191324
Median: mb = 22.80989894559
Median: mc = 22.80989894559

Inradius: r = 7.6910903718
Circumradius: R = 15.40329362924

Vertex coordinates: A[27; 0] B[0; 0] C[12.51985185185; 22.78878628682]
Centroid: CG[13.17328395062; 7.59659542894]
Coordinates of the circumscribed circle: U[13.5; 7.41662285852]
Coordinates of the inscribed circle: I[13; 7.6910903718]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 122.4365590639° = 122°26'8″ = 1.00546884753 rad
∠ B' = β' = 118.7822204681° = 118°46'56″ = 1.06884520891 rad
∠ C' = γ' = 118.7822204681° = 118°46'56″ = 1.06884520891 rad

# How did we calculate this 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. ### 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    