# 6 11 11 triangle

### Acute isosceles triangle.

Sides: a = 6   b = 11   c = 11

Area: T = 31.74990157328
Perimeter: p = 28
Semiperimeter: s = 14

Angle ∠ A = α = 31.65332402637° = 31°39'12″ = 0.55224532615 rad
Angle ∠ B = β = 74.17333798681° = 74°10'24″ = 1.2954569696 rad
Angle ∠ C = γ = 74.17333798681° = 74°10'24″ = 1.2954569696 rad

Height: ha = 10.58330052443
Height: hb = 5.77325483151
Height: hc = 5.77325483151

Median: ma = 10.58330052443
Median: mb = 6.94662219947
Median: mc = 6.94662219947

Inradius: r = 2.26877868381
Circumradius: R = 5.71767126543

Vertex coordinates: A[11; 0] B[0; 0] C[1.63663636364; 5.77325483151]
Centroid: CG[4.21221212121; 1.92441827717]
Coordinates of the circumscribed circle: U[5.5; 1.55991034512]
Coordinates of the inscribed circle: I[3; 2.26877868381]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 148.3476759736° = 148°20'48″ = 0.55224532615 rad
∠ B' = β' = 105.8276620132° = 105°49'36″ = 1.2954569696 rad
∠ C' = γ' = 105.8276620132° = 105°49'36″ = 1.2954569696 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    