# 11 11 17 triangle

### Obtuse isosceles triangle.

Sides: a = 11   b = 11   c = 17

Area: T = 59.3488020186
Perimeter: p = 39
Semiperimeter: s = 19.5

Angle ∠ A = α = 39.40105687537° = 39°24'2″ = 0.68876696519 rad
Angle ∠ B = β = 39.40105687537° = 39°24'2″ = 0.68876696519 rad
Angle ∠ C = γ = 101.1998862493° = 101°11'56″ = 1.76662533498 rad

Height: ha = 10.79105491247
Height: hb = 10.79105491247
Height: hc = 6.98221200219

Median: ma = 13.21993040664
Median: mb = 13.21993040664
Median: mc = 6.98221200219

Inradius: r = 3.04334882147
Circumradius: R = 8.66549899759

Vertex coordinates: A[17; 0] B[0; 0] C[8.5; 6.98221200219]
Centroid: CG[8.5; 2.32773733406]
Coordinates of the circumscribed circle: U[8.5; -1.6832869954]
Coordinates of the inscribed circle: I[8.5; 3.04334882147]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 140.5999431246° = 140°35'58″ = 0.68876696519 rad
∠ B' = β' = 140.5999431246° = 140°35'58″ = 0.68876696519 rad
∠ C' = γ' = 78.80111375075° = 78°48'4″ = 1.76662533498 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.