# 3 4 6 triangle

### Obtuse scalene triangle.

Sides: a = 3   b = 4   c = 6

Area: T = 5.33326822519
Perimeter: p = 13
Semiperimeter: s = 6.5

Angle ∠ A = α = 26.38443297494° = 26°23'4″ = 0.46604934251 rad
Angle ∠ B = β = 36.33660575146° = 36°20'10″ = 0.63441838408 rad
Angle ∠ C = γ = 117.2879612736° = 117°16'47″ = 2.04769153877 rad

Height: ha = 3.55551215013
Height: hb = 2.6666341126
Height: hc = 1.77875607506

Median: ma = 4.87333971724
Median: mb = 4.30111626335
Median: mc = 1.87108286934

Vertex coordinates: A[6; 0] B[0; 0] C[2.41766666667; 1.77875607506]
Centroid: CG[2.80655555556; 0.59325202502]
Coordinates of the circumscribed circle: U[3; -1.54770638621]
Coordinates of the inscribed circle: I[2.5; 0.82204126541]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 153.6165670251° = 153°36'56″ = 0.46604934251 rad
∠ B' = β' = 143.6643942485° = 143°39'50″ = 0.63441838408 rad
∠ C' = γ' = 62.7220387264° = 62°43'13″ = 2.04769153877 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    