# 8.5 6.5 13.5 triangle

### Obtuse scalene triangle.

Sides: a = 8.5   b = 6.5   c = 13.5

Area: T = 21.82334213347
Perimeter: p = 28.5
Semiperimeter: s = 14.25

Angle ∠ A = α = 29.82881284312° = 29°49'41″ = 0.52105990508 rad
Angle ∠ B = β = 22.35662712474° = 22°21'23″ = 0.39901905417 rad
Angle ∠ C = γ = 127.8165600321° = 127°48'56″ = 2.2310803061 rad

Height: ha = 5.1354922667
Height: hb = 6.71548988722
Height: hc = 3.2333099457

Median: ma = 9.70550244719
Median: mb = 10.80221988502
Median: mc = 3.41986985828

Vertex coordinates: A[13.5; 0] B[0; 0] C[7.86111111111; 3.2333099457]
Centroid: CG[7.12203703704; 1.0787699819]
Coordinates of the circumscribed circle: U[6.75; -5.2398780998]
Coordinates of the inscribed circle: I[7.75; 1.53114681638]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 150.1721871569° = 150°10'19″ = 0.52105990508 rad
∠ B' = β' = 157.6443728753° = 157°38'37″ = 0.39901905417 rad
∠ C' = γ' = 52.18443996786° = 52°11'4″ = 2.2310803061 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    