# 7 7 11 triangle

### Obtuse isosceles triangle.

Sides: a = 7   b = 7   c = 11

Area: T = 23.81656986041
Perimeter: p = 25
Semiperimeter: s = 12.5

Angle ∠ A = α = 38.21332107017° = 38°12'48″ = 0.66769463445 rad
Angle ∠ B = β = 38.21332107017° = 38°12'48″ = 0.66769463445 rad
Angle ∠ C = γ = 103.5743578597° = 103°34'25″ = 1.80876999646 rad

Height: ha = 6.80444853154
Height: hb = 6.80444853154
Height: hc = 4.33301270189

Median: ma = 8.52993610546
Median: mb = 8.52993610546
Median: mc = 4.33301270189

Inradius: r = 1.90552558883
Circumradius: R = 5.65880326381

Vertex coordinates: A[11; 0] B[0; 0] C[5.5; 4.33301270189]
Centroid: CG[5.5; 1.4433375673]
Coordinates of the circumscribed circle: U[5.5; -1.32879056191]
Coordinates of the inscribed circle: I[5.5; 1.90552558883]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 141.7876789298° = 141°47'12″ = 0.66769463445 rad
∠ B' = β' = 141.7876789298° = 141°47'12″ = 0.66769463445 rad
∠ C' = γ' = 76.42664214035° = 76°25'35″ = 1.80876999646 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.