# 7 11 16 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 11   c = 16

Area: T = 31.93774388453
Perimeter: p = 34
Semiperimeter: s = 17

Angle ∠ A = α = 21.28799664684° = 21°16'48″ = 0.37114054796 rad
Angle ∠ B = β = 34.77219440319° = 34°46'19″ = 0.60768849107 rad
Angle ∠ C = γ = 123.94880895° = 123°56'53″ = 2.16333022633 rad

Height: ha = 9.12549825272
Height: hb = 5.80768070628
Height: hc = 3.99221798557

Median: ma = 13.27659180474
Median: mb = 11.05766721937
Median: mc = 4.5832575695

Inradius: r = 1.87986728733
Circumradius: R = 9.64438540827

Vertex coordinates: A[16; 0] B[0; 0] C[5.75; 3.99221798557]
Centroid: CG[7.25; 1.33107266186]
Coordinates of the circumscribed circle: U[8; -5.38655289033]
Coordinates of the inscribed circle: I[6; 1.87986728733]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 158.7220033532° = 158°43'12″ = 0.37114054796 rad
∠ B' = β' = 145.2288055968° = 145°13'41″ = 0.60768849107 rad
∠ C' = γ' = 56.05219105004° = 56°3'7″ = 2.16333022633 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    