# 5 9 11 triangle

### Obtuse scalene triangle.

Sides: a = 5   b = 9   c = 11

Area: T = 22.18552991866
Perimeter: p = 25
Semiperimeter: s = 12.5

Angle ∠ A = α = 26.6277478393° = 26°37'39″ = 0.46547371695 rad
Angle ∠ B = β = 53.77884533802° = 53°46'42″ = 0.93986110781 rad
Angle ∠ C = γ = 99.59440682269° = 99°35'39″ = 1.7388244406 rad

Height: ha = 8.87441196746
Height: hb = 4.93300664859
Height: hc = 4.03436907612

Median: ma = 9.7343961167
Median: mb = 7.26329195232
Median: mc = 4.77696960071

Inradius: r = 1.77548239349
Circumradius: R = 5.57880180812

Vertex coordinates: A[11; 0] B[0; 0] C[2.95545454545; 4.03436907612]
Centroid: CG[4.65215151515; 1.34545635871]
Coordinates of the circumscribed circle: U[5.5; -0.93296696802]
Coordinates of the inscribed circle: I[3.5; 1.77548239349]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 153.3732521607° = 153°22'21″ = 0.46547371695 rad
∠ B' = β' = 126.222154662° = 126°13'18″ = 0.93986110781 rad
∠ C' = γ' = 80.40659317731° = 80°24'21″ = 1.7388244406 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 ### 6. Inradius ### 7. Circumradius ### 8. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.