# 6.41 6.41 12.19 triangle

### Obtuse isosceles triangle.

Sides: a = 6.41   b = 6.41   c = 12.19

Area: T = 12.0976809317
Perimeter: p = 25.01
Semiperimeter: s = 12.505

Angle ∠ A = α = 18.03767648456° = 18°2'12″ = 0.3154800933 rad
Angle ∠ B = β = 18.03767648456° = 18°2'12″ = 0.3154800933 rad
Angle ∠ C = γ = 143.9266470309° = 143°55'35″ = 2.51219907877 rad

Height: ha = 3.77443554811
Height: hb = 3.77443554811
Height: hc = 1.98547103063

Median: ma = 9.1966198943
Median: mb = 9.1966198943
Median: mc = 1.98547103063

Inradius: r = 0.96773578022
Circumradius: R = 10.35111580177

Vertex coordinates: A[12.19; 0] B[0; 0] C[6.095; 1.98547103063]
Centroid: CG[6.095; 0.66215701021]
Coordinates of the circumscribed circle: U[6.095; -8.36664477114]
Coordinates of the inscribed circle: I[6.095; 0.96773578022]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.9633235154° = 161°57'48″ = 0.3154800933 rad
∠ B' = β' = 161.9633235154° = 161°57'48″ = 0.3154800933 rad
∠ C' = γ' = 36.07435296912° = 36°4'25″ = 2.51219907877 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    