# 11 11 12 triangle

### Acute isosceles triangle.

Sides: a = 11   b = 11   c = 12

Area: T = 55.31772667438
Perimeter: p = 34
Semiperimeter: s = 17

Angle ∠ A = α = 56.94442688491° = 56°56'39″ = 0.99438649816 rad
Angle ∠ B = β = 56.94442688491° = 56°56'39″ = 0.99438649816 rad
Angle ∠ C = γ = 66.11114623017° = 66°6'41″ = 1.15438626905 rad

Height: ha = 10.05876848625
Height: hb = 10.05876848625
Height: hc = 9.22195444573

Median: ma = 10.11218742081
Median: mb = 10.11218742081
Median: mc = 9.22195444573

Inradius: r = 3.25439568673
Circumradius: R = 6.5622146349

Vertex coordinates: A[12; 0] B[0; 0] C[6; 9.22195444573]
Centroid: CG[6; 3.07331814858]
Coordinates of the circumscribed circle: U[6; 2.65773981083]
Coordinates of the inscribed circle: I[6; 3.25439568673]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 123.0565731151° = 123°3'21″ = 0.99438649816 rad
∠ B' = β' = 123.0565731151° = 123°3'21″ = 0.99438649816 rad
∠ C' = γ' = 113.8898537698° = 113°53'19″ = 1.15438626905 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.