# 11.4 13.7 12.2 triangle

### Acute scalene triangle.

Sides: a = 11.4   b = 13.7   c = 12.2

Area: T = 65.70438590476
Perimeter: p = 37.3
Semiperimeter: s = 18.65

Angle ∠ A = α = 51.83330483861° = 51°49'59″ = 0.90546573557 rad
Angle ∠ B = β = 70.8880147404° = 70°52'49″ = 1.23770919465 rad
Angle ∠ C = γ = 57.28768042099° = 57°17'12″ = 10.9998433514 rad

Height: ha = 11.52769928154
Height: hb = 9.59218042405
Height: hc = 10.7711124434

Median: ma = 11.6522253001
Median: mb = 9.61765222404
Median: mc = 11.02879191147

Vertex coordinates: A[12.2; 0] B[0; 0] C[3.73440163934; 10.7711124434]
Centroid: CG[5.31113387978; 3.59903748113]
Coordinates of the circumscribed circle: U[6.1; 3.9188114609]
Coordinates of the inscribed circle: I[4.95; 3.52329951232]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 128.1676951614° = 128°10'1″ = 0.90546573557 rad
∠ B' = β' = 109.1219852596° = 109°7'11″ = 1.23770919465 rad
∠ C' = γ' = 122.713319579° = 122°42'48″ = 10.9998433514 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    